1、Designation: D 1042 06Standard Test Method forLinear Dimensional Changes of Plastics Under AcceleratedService Conditions1This standard is issued under the fixed designation D 1042; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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. Scope*1.1 This test method is designed to provide a means formeasuring in plastic specimens the dimensional changes
3、re-sulting from exposure to service conditions. In particular, thistest method is suitable for measuring shrinkage or elongationdeveloped under specific oven and water conditionings.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theres
4、ponsibility 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 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to Plas
5、tics3. Terminology3.1 Definitions: Definitions of terms applying to this testmethod appear in Terminology D 883.4. 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
6、outlined inSections 7 and 8.5. Apparatus5.1 Scriber, so constructed that two 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
7、parallel to each other and perpendicular to andintersecting the long axis 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
8、 calibrated by scribing an arc onto an unconditionedsample and measuring this 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 magn
9、ification of atleast 203 and graduated to have a resolution of 0.01 mm.NOTE 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, 1.753 to 2.03 to assist with theplacement of the caliper points onto t
10、he scribed lines5.4 Beaker, having a suitable size for the number ofspecimens to be evaluated and is constructed of a material thatis stable under the test conditions.5.5 Room or Conditioning Chamber, capable of beingmaintained at 23 6 2C and 50 6 5 % RH.5.6 Conditioning Oven, full draft air-circula
11、ting oven, ca-pable of being maintained within 62C of the set temperature.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 5mmin length by 13 6 0.5 mm wide b
12、y 3.0 (-0.0 + 0.2) mm thick.6.2 Three specimens shall be tested for each conditioning.6.3 Individual specimens shall be positioned vertically inthe specified environment.NOTE 4A wire hook inserted in a hole drilled in one end of thespecimen has been found acceptable.1This test method is under the ju
13、risdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved Sept. 1, 2006. Published September 2006. Originallypublished as D 1042 49 T. Last previous edition D 1042 01a.2For referenced ASTM standards, visit t
14、he 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.FIG. 1 Scriber1*A Summary of Changes section appears at the end of this standard.Copyright ASTM Inte
15、rnational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Conditioning and Exposure7.1 Preconditioning7.1.1 Unless otherwise specified in the appropriate materialspecification, precondition specimens at 23 6 2C and 50 65 % relative humidity for a minimum of 40
16、 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 AWater Immersion7.2.1 Specimens shall be immersed
17、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 1h.7.3.2 After removal from the oven, the spe
18、cimens 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 5 % relative humidity.8. Procedure8.1 Immediately following the preconditioning, scribe anarc o
19、f 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). Draw the arcs smoothly, using a pressure consis
20、tentwith 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 surface of the specimen, in the area of the scr
21、ibe 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 distancebetween the original arc and the new arc with either a caliperor the microscope. Measure the separation of the arcs betweencorresponding
22、 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 confined during the period of exposure toaccelerated
23、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 /DI3 100where:LC= percent of linear change,DB= distance between the scribed arcs, andDI= initial scribed dista
24、nce (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 roundrobin, for the purpose of developing an acceptable Precisionand Bias statement. However, R
25、epeatability 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)PA 66 3.10 Expansion 0.108 0.114 0.091 0.104 0.012 0.104PP 3.00 Shrinkage 0.059 0.064 0.072
26、 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 0.055 0.022 0.055TABLE Method BOven ConditioningMaterial Thick.(mm)Exp.or Shr.Spec.
27、1(mm)Spec. 2(mm)Spec. 3(mm)AVG(mm)STDDEV%CH(LC)PA 66 3.10 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 0.250 0.222 0.232 0.235 0.014 0.235PS 3.10 Shrinkage 0.223 0.268 0.321 0
28、.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 test results relate only to thebehavior of the test specimens under the con
29、ditions 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 Dimensions of the specimen;11.1.6 Method of conditioning: A, B, or other;11.1
30、.7 Method of measurement: either caliper or micro-scope;3To participate in the development of precision and bias data, contact the staffmanager of ASTM Committee D20 at ASTM Headquarters.1Original arc2After 37.7C 100F and 100 % humidity3After 60C 140F4Final conditioningFIG. 2 Scribing Test Specimens
31、 for MeasurementD104206211.1.8 Distance between the arcs after each conditioning;and11.1.9 Percent linear expansion or shrinkage (LC).12. Keywords12.1 accelerated service conditions; linear dimensionalchanges; plasticsSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to
32、 this standard since the last issue(D 1042 - 01a) that may impact the use of this standard. (September 1, 2006)(1) Added reference to Section 7 to Significance and Use (4.1).(2) Section 5.1, Scriber: Opened tolerance for scriber length,added bar stock to fabrication choices, removed dimension andtol
33、erance for the diameter of the scriber, changed spelling of“setscrew,” increased tolerance to extension of the needlepoints, and changed the calibration procedure for the measure-ment of the scriber separation distance.(3) Removed the dimensional detail from Fig. 1.(4) Added the choice of using a ca
34、liper and magnifier tomeasure the distance between the scribed lines.(5) Added the relative humidity requirement for the condition-ing chamber in 5.5.(6) Clarified the start of testing after the pre-conditioning time(7.1.2).(7) The choice of using a caliper for measurement was addedto 8.2.(8) Added
35、“(100 mm)” as the definition to the initial scribeddistance, DI in 9.2.(9) Added the method of measurement, either caliper ormicroscope to the report (11.1.7).ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stand
36、ard. Users 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 review
37、ed every 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
38、 technical 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).D1042063
