1、Designation: D1042 06 D1042 12Standard Test Method forLinear Dimensional Changes of Plastics Under AcceleratedService ConditionsCaused by Exposure to Heat andMoisture1This standard is issued under the fixed designation D1042; the number immediately following the designation indicates the year oforig
2、inal adoption or, in the case 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. Scope*1.1 This test method is designed to provide a means for measuring
3、in plastic specimens the dimensional changes resulting fromexposure to service conditions. In particular, this test method is suitable for measuring shrinkage or elongationsuch as shrinkageor expansion, developed under specific ovenheat and water conditionings.1.2 The values stated in SI units are t
4、o be regarded as standard. The values given in parentheses are mathematical conversionsto inch-pound units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respo
5、nsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD59
6、47 Test Methods for Physical Dimensions of Solid Plastics Specimens3. Terminology3.1 Definitions: Definitions of terms applying to this test method appear in Terminology D883.4. Significance and Use4.1 This test method is intended only as a convenient test method for measurement of linear dimensiona
7、l changes in plasticssubjected to defined conditions of test as outlined in Sections 7 and 8.5. Apparatus5.1 Scriber, so constructed that two sharp needle points are rigidly separated by 100 6 0.2 mm. The scriber, as shown in Fig.1, consists of two sharp steel needles, approximately 1.5 mm in diamet
8、er. The needles are to be inserted in drilled holes with theiraxes parallel to each other and perpendicular to and intersecting the long axis of a stainless steel rigid rod or bar stock, 125 6 5mm in length. The needles points shall extend 6 6 2 mm beyond the supporting rod and are held in position
9、by setscrews insertedthrough the ends of the rod. The scriber shall be calibrated by scribing an arc onto an unconditioned sample and measuring thisinitial scribed distance with a calibrated caliper to the nearest 0.1 mm. Thickness of arc lines shall not exceed 0.02 mm.NOTE 2Phonograph needles may b
10、e used as a satisfactory scriber.5.2 Measuring Microscope, having a magnification of at least 20 and graduated to have a resolution of 0.01 mm.NOTE 3For more precise measurements, a micrometer microscope should be used.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics an
11、d is the direct responsibility of Subcommittee D20.50 on Durability of Plastics.Current edition approved Sept. 1, 2006Nov. 15, 2012. Published September 2006December 2012. Originally published as D1042 49 T.T. Last previous editionD1042 01a.D1042 06. DOI: 10.1520/D1042-06.10.1520/D1042-12.2 For refe
12、renced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provid
13、e the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the st
14、andard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.3 Caliper, 6-in., with a readability of 0.01 mm a
15、nd an illuminated desk magnifier, 1.75 to 2.0 to assist with the placementof the caliper points onto the scribed lines5.4 Beaker, having a suitable size for the number of specimens to be evaluated and is constructed of a material that is stableunder the test conditions.5.5 Room or Conditioning Chamb
16、er, capable of being maintained at 23 6 2C and 50 6 5 % 10 % RH.5.6 Conditioning Oven, full draft air-circulating oven, capable 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 m
17、m in length in the direction of test. The preferred specimen size is 125 6 5 mm inlength by 13 6 0.5 mm wide by 3.0 (-0.0 + 0.2) mm thick. Refer to Test Method D5947 for guidance on measuring physicaldimensions of solid plastic specimens.6.2 Three specimens shall be tested for each conditioning.6.3
18、Individual specimens shall be positioned vertically in the specified environment.NOTE 4A wire hook inserted in a hole drilled in one end of the specimen has been found acceptable.7. Conditioning and Exposure7.1 Preconditioning7.1.1 Unless otherwise specified in the appropriate material specification
19、, precondition specimens at 23 6 2C and 50 6 5 %10 % relative humidity for a minimum of 40 h prior to initial scribing.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, specimen
20、s shall be tested within 30 min.7.2 Method AWater Immersion7.2.1 Specimens shall be immersed in water maintained at 23 6 2C for 168 6 1 h.7.2.2 The specimens shall be wiped dry with the absorbent cloth after removal from the water and tested within 3 min.7.3 Method BOven Conditioning7.3.1 Specimens
21、shall be conditioned in an oven at 70 6 2C for 25 6 1 h.7.3.2 After removal from the oven, the specimens shall be tested within 3 min.7.4 Other conditionings for specific service conditions can be used if agreed upon by all parties.7.5 Conduct tests in a standard laboratory atmosphere of 23 6 2C and
22、 50 6 510 % relative humidity.8. Procedure8.1 Immediately following the preconditioning, scribe an arc of 100-mm radius on the surface of the test specimen. Press oneneedle firmly into the specimen to form a center for this and subsequent measurements. The other needle scribes the arc that isused as
23、 a reference for all subsequent measurements (see Fig. 2). Draw the arcs smoothly, using a pressure consistent with thesurface hardness and test conditions to which the specimen is subjected. It is desirable to lightly scratch the surface with the needleso that a sharp, clear arc is defined.NOTE 6A
24、contrasting colored, permanent type marker may be used on the surface of the specimen, in the area of the scribe to aid in defining a sharp,clear arc.8.2 After conditioning, reinsert one needle in the original center and draw a short arc with the other. Measure the distance (DB)between the original
25、arc and the new arc with either a caliper or the microscope. Measure the separation of the arcs betweencorresponding positions, for example, center to center.FIG. 1 ScriberD1042 1228.3 If the test specimen is not flat, flatten it by pressing or clamping it against a plane surface before scribing the
26、 arcs and makingthe measurements. In no case shall the specimen be clamped or otherwise confined during the period of exposure to acceleratedservice conditions.9. Calculation and Measurement9.1 Measure the distance between arcs to the nearest 0.01 mm.9.2 Determine the amount of linear expansion or s
27、hrinkage by the following:LC 5DBDI3100 (1)LC 5DB DI 3100 (1)where:LC = percent of linear change,DB = distance between the scribed arcs, that is, expansion or shrinkage, andDI = initial scribed distance (100 mm).10. Precision and Bias310.1 This test method is in use by a limited number of D20.50 memb
28、ers. Subcommittee D20.50 was not able to locate asufficient number of laboratories willing to conduct a round robin, for the purpose of developing an acceptable Precision and Biasstatement. However, Repeatabilityrepeatability conducted on six materials was developed by one laboratory. Results are as
29、follows:TABLE Method AWater ConditioningMaterial Thick.(mm)Exp.or Shr.Spec.1(mm)Spec. 2(mm)Spec.3(mm)AVG(mm)STDDEV% CH(LC)PA663.10 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
30、 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. 1(mm)Spec. 2(mm)Spec.3(mm)AVG(mm)STDDEV% CH(LC)PA663.10 Shrinkage 0.059 0.064 0.078 0.067
31、 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 0.271 0.049 0.271PMMA 2.98 Shrinkage 0.170 0.189 0.147 0.169 0.021 0.1693 To participate in
32、the development of precision and bias data, contact the staff manager of ASTM Committee D20 at ASTM Headquarters.1Original arc2After 37.7C 100F(100F) and 100 % humidity3After 60C 140F (140F)4Final conditioningFIG. 2 Scribing Test Specimens for MeasurementD1042 12311. Report11.1 The test report shall
33、 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 the behavior of the test specimens under the conditions of this test;11.1.4 Identification of the material tested, including the manufacturer, designation
34、, type of material, the specimen orientationwith respect to any anisotropy, and anything unique to the material;11.1.5 Dimensions of the specimen;11.1.6 Method of conditioning: A, B, or other;11.1.7 Method of measurement: either caliper or microscope;11.1.8 Distance (DB) between the arcs after each
35、conditioning; and11.1.9 Percent linear expansion or shrinkage (LC ).12. Keywords12.1 accelerated service conditions; linear dimensional changes; plasticsSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D1042 - 01aD1042 - 06) that m
36、ay impact the use of this standard. (September 1, 2006)(November 15, 2012)(1) Added reference to Section 7 to Significance and Use (4.1). Changed relative humidity tolerance from 65 % to 610 %.(2) Section 5.1, Scriber: Opened tolerance for scriber length, added bar stock to fabrication choices, remo
37、ved dimension andtolerance for the diameter of the scriber, changed spelling of “setscrew,” increased tolerance to extension of the needle points, andchanged the calibration procedure for the measurement of the scriber separation distance.Improved the linkage between symbolsand reported properties.(
38、3) Removed the dimensional detailChanged title and scope from Fig. 1.“Accelerated Service Conditions” to “Heat and Moisture.”(4) Added the choice of using a caliper and magnifier to measure the distance between the scribed lines.reference Test MethodD5947.(5) Added the relative humidity requirement
39、for the conditioning chamber in 5.5.Revised Figure 2.(6) Clarified the start of testing after the pre-conditioning time (7.1.2).(7) The choice of using a caliper for measurement was added to 8.2.(8) Added “(100 mm)” as the definition to the initial scribed distance, DI in 9.2.(9) Added the method of
40、 measurement, either caliper or microscope 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 standard. Users of this standard are expressly advised that determination of the validity of any s
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