1、Designation: D 1204 08Standard Test Method forLinear Dimensional Changes of Nonrigid ThermoplasticSheeting or Film at Elevated Temperature1This standard is issued under the fixed designation D 1204; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This tes
3、t method covers the measurement of changes inlinear dimensions of nonrigid thermoplastic sheeting or filmthat result from exposure of the material to specified conditionsof elevated temperature and time.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not pu
4、rport to address all of thesafety concerns, 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.NOTE 1This test method and ISO 11501 address
5、 the same matter, butdiffer in technical content (and results cannot be directly comparedbetween the two methods).2. Referenced Documents2.1 ASTM Standards:2D 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 2732 Test Method for Unrestrained Linear ThermalShr
6、inkage of Plastic Film and SheetingD 4000 Classification System for Specifying Plastic Mate-rials2.2 ISO StandardISO 11501 Plastics: Film and SheetingDetermination ofDimensional Change on Heating33. Terminology3.1 DefinitionsTerms applicable to this test method aredefined in Terminology D 883.4. Sig
7、nificance and Use4.1 This test method is particularly applicable to nonrigidthermoplastic sheeting or film made by the calender or extru-sion process. The test gives an indication of lot-to-lot unifor-mity as regards to the degree of internal strains introducedduring processing.4.2 The heating mediu
8、m in this test method is air and maynot yield the same results as Test Method D 2732, which usesa liquid medium.4.3 Before proceeding with this test method, referenceshould be made to the specification of the material being tested.Any test specimen preparation, conditioning, dimensions, ortesting pa
9、rameters, or combination thereof, covered in therelevant ASTM material specification shall take precedenceover those mentioned in this test method. If there are norelevant ASTM material specifications, then the default condi-tions apply. Table 1 of Classification System D 4000 lists theASTM material
10、 standards that currently exist.5. Apparatus5.1 OvenA mechanical convection oven capable of main-taining a temperature of 100 6 1C.5.2 Scale, graduated in 0.25-mm (0.01-in.) divisions, 30 cm(12 in.) or more in length.5.3 Thermometer, graduated in 1C divisions, with a rangesuitable for the test tempe
11、rature used.5.4 Timer, graduated in minutes.5.5 Template, 25 by 25 cm (10 by 10 in.), for cutting testspecimens.5.6 Heavy Paper Sheets, approximately 40 by 40 cm (15 by15 in.), with smooth, wrinkle- and crease-free surfaces.5.7 Talc, finely ground.1This test method is under the jurisdiction of ASTM
12、Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film and Sheeting.Current edition approved Nov. 1, 2008. Published November 2008. Originallyapproved in 1952. Last previous edition approved in 2007 as D 1204 - 07.2For referenced ASTM standards, visit the ASTM websi
13、te, 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.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:
14、/www.ansi.org.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.6. Test Specimens6.1 The test specimens shall be two pieces of the sheeting orfilm 25 by 25 cm (10 by 10
15、in.), cut with the aid of thetemplate, one from either of the two transverse edges and onefrom the center of the sheet as shown in Fig. 1. Each specimenshall be marked to show the direction of calendering orextrusion. The midpoint of each edge shall be marked for useas a reference point when final m
16、easurements are made.7. Conditioning7.1 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 A ofPractice D 618 unless otherwise specified by agreement or therelevant ASTM material specificat
17、ion. In cases of disagree-ment, the tolerances shall be 61C (61.8F) and 65%relative humidity.8. Procedure8.1 Place each specimen on the heavy paper that has beenlightly dusted with talc, and cover with a second piece ofdusted paper. Fasten the papers together with paper clips.NOTE 2The paper should
18、be well dusted, and the specimens shouldnot be restricted either by the paper or the clips. It is imperative that thespecimens be free to change shape as strains are relieved during theperiod of test.8.2 Place the paper-plastic sandwiches horizontally in theoven at the temperature and for the length
19、 of time applicable tothe material being tested. Sandwiches must not be stacked, asthis may restrict movement of the plastic between the papers.8.3 At the end of the oven-exposure period, recondition thespecimens a minimum of 1 h at the temperature and humidityused for the initial conditioning. Remo
20、ve the papers andmeasure the distance between the opposite edges of thespecimens at the reference marks to the nearest 0.25 mm (0.01in.). Shorter reconditioning times may be used if it can beshown that equivalent results are obtained.9. Calculations9.1 Calculate the linear dimensional change as foll
21、ows:Linear change, % 5 Df2 Do!/Do# 3 100 (1)where:Df= final length (or width) of specimen, mm (or in.) aftertest, andDo= original length (or width) of specimen, mm (or in.).A negative value denotes shrinkage, and a positive valueindicates expansion.9.2 Average the values obtained for each direction.
22、10. Report10.1 Report the following information:10.1.1 Identification of the material tested,10.1.2 Test conditions (time and temperature), includingconditioning of test specimens, and10.1.3 Average percentage linear change in both the paralleland the transverse direction of processing.11. Precision
23、 and Bias11.1 A task group will be formed to develop the precisionand bias statement for this test method.12. Keywords12.1 film; sheeting; temperature; thermoplasticSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D 1204 - 07) that
24、 may impact the use of this standard. (November 1, 2008)(1) Revised Section 7 and 8.3.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 t
25、he 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 five years andif not revised, either reapproved or withdrawn. Yo
26、ur 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 technical committee, which you may attend. If you feel that your comment
27、s 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 mul
28、tiple 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).Points a, b and x, y are reference marks at midpoint of test specimen edges.FIG. 1 Method of Cutting Test Specimens from SampleD1204082
