ASTM D1042-2012(2017) Standard Test Method for Linear Dimensional Changes of Plastics Caused by Exposure to Heat and Moisture《热量和湿气暴露导致塑料线性尺寸变化的标准试验方法》.pdf

1、Designation: D1042 12 (Reapproved 2017)Standard Test Method forLinear Dimensional Changes of Plastics Caused byExposure to Heat and Moisture1This standard is issued under the fixed designation D1042; the number immediately following the designation indicates the year oforiginal adoption or, in the c

2、ase 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.1. Scope1.1 This test method is designed to provide a means formeasuring in plastic specimens the dim

3、ensional changes suchas shrinkage or expansion, developed under specific heat andwater conditionings.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not co

4、nsidered standard.1.3 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 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to u

5、se.NOTE 1There is no known ISO equivalent to this standard.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations

6、issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD5947 Test Methods for Physical Dimensions of SolidPlastics Specimens3. Terminology3.1 Definitions: Definitions of terms applying to this

7、testmethod appear in Terminology D883.4. Significance and Use4.1 This test method is intended only as a convenient testmethod for measurement of linear dimensional changes inplastics subjected to defined conditions of test as outlined inSections 7 and 8.5. Apparatus5.1 Scriber, so constructed that t

8、wo sharp needle points arerigidly separated by 100 6 0.2 mm. The scriber, as shown inFig. 1, consists of two sharp steel needles, approximately 1.5mm in diameter. The needles are to be inserted in drilled holeswith their axes parallel to each other and perpendicular to andintersecting the long axis

9、of a stainless steel rigid rod or barstock, 125 6 5 mm in length. The needles points shall extend6 6 2 mm beyond the supporting rod and are held in positionby setscrews inserted through the ends of the rod. The scribershall be calibrated by scribing an arc onto an unconditionedsample and measuring t

10、his initial scribed distance with acalibrated caliper to the nearest 0.1 mm. Thickness of arc linesshall not exceed 0.02 mm.NOTE 2Phonograph needles may be used as a satisfactory scriber.5.2 Measuring Microscope, having a magnification of atleast 20 and graduated to have a resolution of 0.01 mm.NOTE

11、 3For more precise measurements, a micrometer microscopeshould be used.5.3 Caliper, 6-in., with a readability of 0.01 mm and anilluminated desk magnifier, 1.75 to 2.0 to assist with theplacement of the caliper points onto the scribed lines5.4 Beaker, having a suitable size for the number of speci-me

12、ns to be evaluated and is constructed of a material that isstable under the test conditions.5.5 Room or Conditioning Chamber, capable of being main-tained at 23 6 2C and 50 6 10 % RH.5.6 Conditioning Oven, full draft air-circulating oven, ca-pable of being maintained within 62C of the set temperatur

13、e.5.7 Absorbent Material, cloth or paper suitable for drying.6. Test Specimens6.1 Specimens shall not be less than 110 mm in length in thedirection of test. The preferred specimen size is 125 6 5mm1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsib

14、ility of Subcommittee D20.50 on Durability of Plastics.Current edition approved Aug. 1, 2017. Published August 2017. Originallypublished as D1042 49T. Last previous edition D1042 12. DOI: 10.1520/D1042-12R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Custome

15、r Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA

16、19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Te

17、chnical Barriers to Trade (TBT) Committee.1in length by 13 6 0.5 mm wide by 3.0 (-0.0 + 0.2) mm thick.Refer to Test Method D5947 for guidance on measuringphysical dimensions of solid plastic specimens.6.2 Three specimens shall be tested for each conditioning.6.3 Individual specimens shall be positio

18、ned vertically inthe specified environment.NOTE 4A wire hook inserted in a hole drilled in one end of thespecimen has been found acceptable.7. Conditioning and Exposure7.1 Preconditioning7.1.1 Unless otherwise specified in the appropriate materialspecification, precondition specimens at 23 6 2C and

19、50 6 10% relative humidity for a minimum of 40 h prior to initialscribing.NOTE 5If moisture equilibrium is required prior to preconditioning,refer to the specific material specifications.7.1.2 After removal from the pre-conditioning environment,specimens shall be tested within 30 min.7.2 Method AWat

20、er Immersion7.2.1 Specimens shall be immersed in water maintained at23 6 2C for 168 6 1h.7.2.2 The specimens shall be wiped dry with the absorbentcloth after removal from the water and tested within 3 min.7.3 Method BOven Conditioning7.3.1 Specimens shall be conditioned in an oven at 70 62C for 25 6

21、 1h.7.3.2 After removal from the oven, the specimens shall betested within 3 min.7.4 Other conditionings for specific service conditions canbe used if agreed upon by all parties.7.5 Conduct tests in a standard laboratory atmosphere of 236 2C and 50 6 10 % relative humidity.8. Procedure8.1 Immediatel

22、y following the preconditioning, scribe anarc of 100-mm radius on the surface of the test specimen. Pressone needle firmly into the specimen to form a center for thisand subsequent measurements. The other needle scribes the arcthat is used as a reference for all subsequent measurements (seeFig. 2).

23、Draw the arcs smoothly, using a pressure consistentwith the surface hardness and test conditions to which thespecimen is subjected. It is desirable to lightly scratch thesurface with the needle so that a sharp, clear arc is defined.NOTE 6Acontrasting colored, permanent type marker may be used onthe

24、surface of the specimen, in the area of the scribe to aid in defining asharp, clear arc.8.2 After conditioning, reinsert one needle in the originalcenter and draw a short arc with the other. Measure the distance(DB) between the original arc and the new arc with either acaliper or the microscope. Mea

25、sure the separation of the arcsbetween corresponding positions, for example, center to center.8.3 If the test specimen is not flat, flatten it by pressing orclamping it against a plane surface before scribing the arcs andmaking the measurements. In no case shall the specimen beclamped or otherwise c

26、onfined during the period of exposure toaccelerated service conditions.9. Calculation and Measurement9.1 Measure the distance between arcs to the nearest 0.01mm.9.2 Determine the amount of linear expansion or shrinkageby the following:LC5 DB DI3100 (1)where:LC= percent of linear change,DB= distance

27、between the scribed arcs, that is, expansion orshrinkage, andDI= initial scribed distance (100 mm).10. Precision and Bias310.1 This test method is in use by a limited number ofD20.50 members. Subcommittee D20.50 was not able to locatea sufficient number of laboratories willing to conduct a roundrobi

28、n, for the purpose of developing an acceptable Precisionand Bias statement. However, repeatability conducted on sixmaterials was developed by one laboratory. Results are asfollows:TABLE Method AWater ConditioningMaterial Thick.(mm)Exp.or Shr.Spec.1(mm)Spec. 2(mm)Spec.3(mm)AVG(mm)STDDEV%CH(LC)PA663.1

29、0 Expansion 0.108 0.114 0.091 0.104 0.012 0.104PP 3.00 Shrinkage 0.059 0.064 0.072 0.065 0.007 0.065ABS 2.98 Expansion 0.119 0.308 0.131 0.186 0.106 0.186PC 3.15 Shrinkage 0.051 0.067 0.138 0.085 0.046 0.085PS 3.10 Shrinkage 0.054 0.072 0.065 0.064 0.009 0.064PMMA 2.98 Expansion 0.056 0.032 0.076 0.

30、055 0.022 0.0553To participate in the development of precision and bias data, contact the staffmanager of ASTM Committee D20 at ASTM Headquarters.FIG. 1 Scriber1Original arc2After 37.7C (100F) and 100 % humidity3After 60C (140F)4Final conditioningFIG. 2 Scribing Test Specimens for MeasurementD1042 1

31、2 (2017)2TABLE Method BOven ConditioningMaterial Thick.(mm)Exp.or Shr.Spec. 1(mm)Spec. 2(mm)Spec.3(mm)AVG(mm)STDDEV%CH(LC)PA663.10 Shrinkage 0.059 0.064 0.078 0.067 0.010 0.067PP 3.00 Shrinkage 0.169 0.171 0.158 0.166 0.007 0.166ABS 2.98 Shrinkage 0.150 0.185 0.128 0.154 0.029 0.154PC 3.15 Shrinkage

32、 0.250 0.222 0.232 0.235 0.014 0.235PS 3.10 Shrinkage 0.223 0.268 0.321 0.271 0.049 0.271PMMA 2.98 Shrinkage 0.170 0.189 0.147 0.169 0.021 0.16911. Report11.1 The test report shall include the following information:11.1.1 A reference to this standard;11.1.2 Date of testing;11.1.3 A statement that te

33、st results relate only to thebehavior of the test specimens under the conditions of this test;11.1.4 Identification of the material tested, including themanufacturer, designation, type of material, the specimenorientation with respect to any anisotropy, and anything uniqueto the material;11.1.5 Dime

34、nsions of the specimen;11.1.6 Method of conditioning: A, B, or other;11.1.7 Method of measurement: either caliper or micro-scope;11.1.8 Distance (DB) between the arcs after each condition-ing; and11.1.9 Percent linear expansion or shrinkage (LC).12. Keywords12.1 accelerated service conditions; linea

35、r dimensionalchanges; plasticsASTM 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 the validity of any such patent rights, and the riskof in

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39、ting 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 12 (2017)3