1、Designation: D 3291 97 (Reapproved 2003)Standard Practice forCompatibility of Plasticizers in Poly(Vinyl Chloride) PlasticsUnder Compression1This standard is issued under the fixed designation D 3291; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、case of revision, the 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 practice determines the compatibility of plasticiz-ers in poly(vinyl chloride) pl
3、astics by rating the amount ofplasticizer that spews due to compressional stress set up insidea 180 loop bend.NOTE 1Ingredients other than plasticizer can spew from a totalformulation.1.2 The text of this practice references notes and footnotesthat provide explanatory material. These notes and footn
4、otes(excluding those in tables and figures) shall not be consideredas requirements of this practice.1.3 The values as stated in SI units are to be regarded as thestandard. The values in brackets are given for information only.1.4 This standard does not purport to address all of thesafety concerns, i
5、f 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 2There are no ISO standards covering the primary subject ofthis practice.2. Referenc
6、ed Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 1600 Terminology for Abbreviated Terms Relating toPlastics23. Terminology3.1 GeneralDefinitions are in accordance with Terminol-ogy D 883 and abbreviations with Terminology D 1600, unlessotherwise indicated.4. Summary of Practic
7、e4.1 Test specimens of plasticized poly(vinyl chloride) sheetare bent through an arc of approximately 180. The innerradius of the bend is equal to the thickness of the specimen.These bent specimens are secured in a jig designed to holdthem in the desired conformation. At specified intervals oftime,
8、a specimen is removed, bent 360 in the oppositedirection, and the former inside of the loop (now the outside)is examined for evidence of plasticizer spew.5. Significance and Use5.1 Plasticizers may become less compatible in poly(vinylchloride) resin when fused compound is subjected to compres-sive s
9、tress.5.1.1 This test subjects a standard test specimen to a definitedeformation and allows qualitative determination of theamount of spew which may occur over a period of time.5.1.2 An apparent decrease in compatibility of plasticizerswith subsequent exudation can cause excessive dirt pickup,marrin
10、g of lacquered or varnished surfaces, sticky feel, and anumber of other associated problems.5.1.3 When a plasticized poly(vinyl chloride) sheet isstressed in compression by bending it through 180, the stressmay be relieved by migration of the plasticizer from thecompressed area (inside of bend) to t
11、he area in tension (outsideof bend). If these compressive stresses cannot be relievedrapidly by internal migration of plasticizer, then plasticizer willspew. The internal migration of plasticizer will continue andwhen a deficiency of plasticizer occurs at the compressed areaspewed plasticizer will b
12、e reabsorbed. Certain plasticizers mayspew and be reabsorbed quite rapidly. Less compatible plasti-cizers may spew early and continue to spew throughout thetest. A test of one weeks duration is used for screening, whilean extended test of seven weeks duration is used for acomplete profile.NOTE 3Othe
13、r test conditions of time, temperature, or relative humid-ity may be agreed upon between the seller and the purchaser.6. Apparatus6.1 Bending Test Jig, as shown in Fig. 1.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.15
14、on Thermoplastic Materials(Section D20.15.07).Current edition approved July 10, 2003. Published September 2003. Originallyapproved in 1974. Last previous edition approved in 1997 as D 3291 97.2Annual Book of ASTM Standards, Vols 08.01 and 08.04.1*A Summary of Changes section appears at the end of th
15、is standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Cigarette Papers, cut in half to be approximatelysquare.37. Specimen Preparation7.1 Cut test specimens 12.7 by 25.4 mm 12 by 1 in. froma plasticized poly(vinyl chloride)
16、sheet 1.9 6 0.1 mm 0.075 60.005 in. thick, taking care to ensure the long edges areparallel.NOTE 4Optimum fusion conditions of temperature and time vary withplasticizer and resin type as well as other additives. The processingconditions must be agreed upon by the seller and the purchaser.8. Conditio
17、ning8.1 Test specimens shall be conditioned at 23 6 2C 73.46 3.6F and 50 6 5 % relative humidity for 24 h prior totesting.9. Procedure9.1 Fold the conditioned specimens in half, short endstogether and place the loop end in the jig with the spacer barequal to four times the nominal specimen thickness
18、7.6 mm0.300 in.as shown in Fig. 2. Leave about 4.75 mm 316 in.of the ends outside jig. The loop inside the jig should besmooth and continuous and no evidence of cracking should beseen on the outside of the loop.NOTE 5Specimen must be thoroughly fused to give meaningfulresults. Collapse of the loop i
19、s one indication of incomplete fusion.9.2 Mark the time of starting the test.9.3 Place the loop jig containing the specimens in thechamber at 23 6 2C 73.4 6 3.6F and 50 6 5 % relativehumidity.9.4 Test individual specimens for 4 h, 24 h, and 7 days.9.5 At the end of the testing period, remove a speci
20、menfrom the jig and fold the loop in the opposite direction aroundindex finger, so that the inside of the loop in the jig is nowoutside. Examine the loop area for evidence of spew by wipingthe loop area thoroughly with a cigarette paper held around aclean, dry finger.9.6 Rate spew according to the a
21、ppearance of the cigarettepaper immediately after wiping.9.7 Subject those specimens which show exudation after the7-day test period to long-term testing by repeating 8.1-9.6.Start seven specimens together with examination of onespecimen each week for 7 weeks.10. Interpretation of Results10.1 Assign
22、 a rating in accordance with the following:3An example of a satisfactory brand is white OCB paper from Reynolds.A Drill and countersink for 6.35-mm 14-in. flat head machine screwB Drill and tap to receive 6.35-mm 14-in. machine screwC May be any convenient length up to 457 mm 18 in.MaterialOil-harde
23、ning precision ground tool and die steelFIG. 1 Bending Test JigD 3291 97 (2003)2Description of Cigarette PaperAmount ofExudationGradingNo mark on paper or visible evidence in loop. none 0Oily mark on paper very faint and discontin-uous.slight 1Wetted area may appear saturated in smallspots, although
24、 much of it is not saturated.moderate 2Total wetted area is saturated by continuousfilm. Large puddle of plasticizer over entirewetted area.heavy/dripping 311. Report11.1 Report the following information:11.1.1 Description of the sample, and11.1.2 Ratings for each time period.12. Precision and Bias4
25、12.1 ReproducibilityMultilaboratory test results on speci-mens prepared in a single laboratory are reproducible to within61.0 grading unit at two standard deviations when the speci-mens are actually 1 or 2. If specimens are actually 0 or 3,practically all tests agreed exactly.12.2 BiasThe bias has n
26、ot been determined.13. Keywords13.1 plasticizer compatibility; plasticizers; poly(vinylchloride)SUMMARY OF CHANGESThis section identifies the location of selected changes to this practice. For the convenience of the user,Committee D20 has highlighted those changes that may impact the use of this pra
27、ctice. This section may alsoinclude descriptions of the changes or reasons for the changes, or both.D 3291 97: (1) Section 1.2 added.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standar
28、d 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 five years andif
29、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 technical committee, whic
30、h 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,Un
31、ited 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).4Round-robin data for this practice are available from ASTM Headquarters.Request RR: D20-1037.FIG. 2 Perspective Drawing Showing Sample Mounted in JigD 3291 97 (2003)3
