1、Designation: F 392 93 (Reapproved 2004)Standard Test Method forFlex Durability of Flexible Barrier Materials1This standard is issued under the fixed designation F 392; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 covers the determination of the flexresistance of flexible barrier materials. Pinhole formation is thec
3、riterion presented for measuring failure, but other tests such asgas-transmission rates can be used in place of the pinhole test.1.2 This 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
4、 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in 5.7.2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 722 Test Method for Grease Resistanc
5、e of PaperE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Summary of Test Method3.1 Specimens of flexible materials are flexed at standardatmospheric conditions (23C and 50 % relative humidity),unless otherwise specified. Flexing conditions and num
6、ber andseverity of flexing strokes vary with the type of structure beingtested. The flexing action consists of a twisting motion fol-lowed, in most cases, by a horizontal motion, thus, repeatedlytwisting and crushing the film. The frequency is at a rate of 45cpm.3.2 Flex failure is determined by mea
7、suring the pinholesformed in the structure. These pinholes are determined byusing colored turpentine and allowing it to stain through theholes onto a white backing. In addition, other failure criteriasuch as gas permeation or moisture-vapor transmission can beused at the discretion of the tester.3.3
8、 The various test conditions are summarized as follows:3.3.1 Condition A Full flex for 1 h (that is, 2700 cycles).3.3.2 Condition B Full flex for 20 min (that is, 900cycles).3.3.3 Condition C Full flex for 6 min (that is, 270 cycles).3.3.4 Condition D Full flex for 20 cycles.3.3.5 Condition E Partia
9、l flex only for 20 cycles.4. Significance and Use4.1 This test method is valuable in determining the resis-tance of flexible-packaging materials to flex-formed pinholefailures.4.2 This test method does not measure any abrasion com-ponent relating to flex failure.4.3 Physical holes completely through
10、 the structure are theonly failures measured by the colored-turpentine-pinhole por-tion of this test. Failures in the integrity of one of the plies ofa multi-ply structure will not be determined by the colored-turpentine test. Gas permeation or moisture vapor transmissiontests, or both, can be used
11、in conjunction with the flex test tomeasure the loss of ply integrity. However, any permeation testrequiring a pressure differential will not measure the perme-ation coefficient in the presence of pinholes.4.3.1 The various conditions described in this procedure areto prevent testing a structure und
12、er conditions that either givetoo many holes to effectively count and be significant (nor-mally greater than 50), or too few to be significant (normallyless than five per sample).4.4 Measurements on nylon film, possibly because of itshydrophilic nature, have not shown good reproducibility (be-tween
13、laboratories), although the repeatability of the datawithin a laboratory was good.5. Apparatus and Reagent5.1 Flex Tester,3designed so that it can be set up inaccordance with the specifications listed in Section 8. Thisapparatus shall consist essentially of a 90-mm (3.5-in.) diam-eter stationary man
14、drel and a 90-mm diameter movable man-drel spaced at a distance of 180 mm (7 in.) apart fromface-to-face at the starting position (that is, maximum distance)of the stroke. Mandrels shall contain vents to prevent pressur-ization of samples. The specimen supporting shoulders on the1This test method is
15、 under the jurisdiction of ASTM Committee F02 on FlexibleBarrier Materials and is the direct responsibility of Subcommittee F02.20 onPhysical Properties.Current edition approved May 15, 1993. Published August 1993. Originallypublished as F 392 74. Last previous edition F 392 74 (1987).2For reference
16、d 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 standards Document Summary page onthe ASTM website.3The Gelbo Tester, which is capable of producing the prescribed flexing act
17、ion,available from the United States Testing Co., Inc., 1415 Park Ave., Hoboken,NJ 07030, or its equivalent, has been found satisfactory for this test method.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.mandrels shall be 13 mm (0.
18、5 in.) wide. The motion of themovable mandrel is controlled by a grooved shaft to which itis attached. For the full or maximum stroke the groove isdesigned to give a twisting motion of 440 in the first 90 mmof the stroke of the movable mandrel, followed by a straighthorizontal motion of 65 mm (2.5 i
19、n.), so that at the closedposition the mandrels are 25 mm (1 in.) apart. The motion ofthe machine is reciprocal with a full cycle consisting of theforward and return strokes. The machine operates at 45 cpm.5.1.1 Fig. 1 shows the planar evolution of the helical groovein the driven shaft to give the r
20、equired 440 (37 helix angle)twisting motion and the straight horizontal motion.5.1.2 For the partial flex used with Condition E the movablehead is set to travel only 80 mm (3.25 in.) of the 180-mm(7-in.) spacing. Therefore, only approximately 90 % of thetwisting stroke is utilized giving a twisting
21、motion of only400, and none of the horizontal stroke is utilized.5.2 Tape, flexible, double-sided, pressure-sensitive, notmore than 13 mm (0.5 in.) wide.5.3 Template, for cutting 200 by 280-mm (8 by 11-in.)samples.5.4 Paint Brush, large, 50 to 150 mm wide.5.5 Tissue Paper, absorbent.5.6 White Paper,
22、 such as uncoated bond paper, at least aslarge as the film samples.5.7 Turpentine (Colored, Water-Free)To 100 mL of puregum spirits of turpentine (chemically pure grade, sp gr 0.860 to0.875 at 15C) add5gofanhydrous calcium chloride (CaCl2)and 1.0 g of oil-soluble red dye. Stopper the container, shak
23、ewell, and let stand for at least 10 h, shaking occasionally. Thenfilter through a dry filter paper at a temperature of approxi-mately 21C, and store in an airtight bottle.NOTE 1Caution: Use of these materials requires that appropriatesafeguards be used to avoid hazards of skin contact, inhalation,
24、andflammability.6. Test SpecimensAll Conditions6.1 Cut the samples into 200 by 280-mm (8 by 11-in.) flatsheets with the 200-mm dimension in the direction to be tested.This will also be in the direction of the flex-tester axis.6.2 Flex test four specimens in their machine direction andfour in their t
25、ransverse direction. In addition, test a control setof four, adjacent, unflexed specimens (either direction) forpinholes.6.3 Do not seal or tape the sides of the specimens, but leavethem open. Use double-sided pressure-sensitive tape, not morethan 13 mm (0.5 in.) wide, to attach the unsealed specime
26、n inthe shape of a cylinder to the flex-tester mandrels.7. Conditioning7.1 Condition the specimens for at least 24 h at 50 6 5%relative humidity and 23 6 2C, unless otherwise specified asagreed upon between the purchaser and the seller. (See PracticeD 618 for other standard atmospheric conditions.)F
27、IG. 1 Planar Evolution of Gelbo Shaft Helical Groove (31.8-mm (1.25-in.) Diameter Shaft)F 392 93 (2004)28. Procedure8.1 Flexing:8.1.1 Atmospheric ConditionsConduct flexing at the stan-dard atmospheric conditions of 23C and 50 % relative humid-ity, unless otherwise specified.8.1.2 Condition A:8.1.2.1
28、 Flex Tester SetupSetup the flex tester for maxi-mum throw and twisting action. This setup gives a twistingmotion of 440 in the first 90 mm (3.5 in.) of stroke, and isfollowed by a straight horizontal motion of 65 mm (2.5 in.) at45 cpm. With this setup, space the face of the moving mandrelat a dista
29、nce of 180 mm (7 in.) from the face of the stationarymandrel when the moving mandrel is at its starting position. Inthe closest position the moving mandrel is 25 mm (1 in.) fromthe stationary mandrel.8.1.2.2 FlexingAttach the flexible barrier specimen to theflex-tester mandrels, which have been line
30、d with double-sidedpressure-sensitive tape. Turn the flex tester on, and allow thespecimen to flex for1hat45cpm(that is, 2700 cycles).8.1.3 Condition B Test conditions are the same as Con-dition A, except that the flex period is 20 min at 45 cpm (thatis, 900 cycles at full flex and twisting action).
31、8.1.4 Condition C Test conditions are the same as Con-dition A, except that the flex period is 6 min at 45 cpm (that is,270 cycles at full flex and twisting action).8.1.5 Condition D Test conditions are the same as Con-ditionA, except that the flex period is 20 cycles at 45 cpm (thatis, 20 cycles at
32、 full flex and twisting action).8.1.6 Condition E Set up the flex tester for the partial flexdescribed in 5.1.2. Here the movable head is set to travel only80 mm (3.25 in.) of the 180-mm (7-in.) spacing (the distancebetween the mandrels at their maximum separation or startingposition). Therefore, on
33、ly about 90 % of the twisting strokegiving a twisting motion of only 400 is utilized and none ofthe horizontal stroke is utilized. When the mandrels are at theirclosest position they will be 95 mm (3.75 in.) apart. The partialflex period under this “short stroke” setup will be 20 cycles at45 cpm.8.2
34、 Pinhole Count:8.2.1 Remove the flexible barrier specimen from the flextester and mark the 150 by 200-mm (6 by 8-in.) center area ofwhite paper corresponding with the center area of the specimenwith the 150-mm (6-in.) dimension in the flex tester-axisdirection.8.2.2 Tape the specimen to the sheet of
35、 white paper againsta flat surface.8.2.3 Paint the specimen with colored turpentine solutionusing multiple strokes of the brush and allow to set for 1 min.8.2.4 After 1 min, wipe the colored turpentine off withabsorbent tissue paper, pressing the specimen against the whitebacking while wiping.8.2.5
36、Remove the specimen from the paper and count eachstrike-through on the paper as a pinhole. Where color patternsoverlap, but distinct center marks are seen, count as separatepinholes. Count all strike-throughs regardless of size, even ifthey are pin-point size, as pinholes. Count only the pinholes in
37、the 150 by 200-mm (6 by 8-in.) area.9. Report9.1 The report shall include the following:9.1.1 Individual values and average pinholes per 300cm2(48 in.2) on quadruplicate determinations in machinedirection and separately in transverse direction,9.1.2 Any unusual failures such as tears,9.1.3 On each s
38、ample under test measure the pinholes of thefour unflexed specimens using procedure of Section 8 (this willdetermine if some pinholes are already in the film that are notthe result of flexing). Report the individual values and averageof these data as“ Pinholes on Unflexed Control.”9.1.4 Test method
39、used, including the number of cycles andwhether full or partial flex was used.9.1.5 Sample conditioning and test conditions used, and9.1.6 Where applicable, sample thickness and structure.10. Precision and Bias410.1 PrecisionData presented in Table 1 is based on around-robin series of tests conducte
40、d in 1992 in accordancewith Practice E 691, involving four materials tested by fivelaboratories. For each material, all the samples were preparedat one source, but the individual specimens were prepared andtested at the laboratory that provided the results. Each testresult is based upon quadruplicat
41、e determinations in themachine direction of the material. Each laboratory obtainedtwo replicates for each material.10.2 BiasThere are no recognized standards by which toestimate bias of this test method.11. Keywords11.1 barrier; barrier materials; flex crack; flex resistance;flexible; pinhole4Suppor
42、ting data are available from ASTM Headquarters. Request RR:F02-1011.TABLE 1 Pinhole DataNOTE 1Values expressed in pinholes/300 cm2(48 in.2).Material DescriptionTestConditionAverage srAsRB0.8 Mil PVdC ctd Cellophane D 3.45 1.47 2.810.92 Mil Oriented Polyester C 3.18 0.87 1.490.48 Mil Oriented Polyest
43、er C 0.18 0.24 3.691.5 Mil Low-Density Polyethylene C 8.15 1.24 7.25Asr= within-laboratory deviation.BsR= between-laboratory deviation.F 392 93 (2004)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Use
44、rs of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every
45、 five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technic
46、al committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 392 93 (2004)4
