1、Designation: D3291 11Standard Practice forCompatibility of Plasticizers in Poly(Vinyl Chloride) PlasticsUnder Compression1This standard is issued under the fixed designation D3291; 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 () 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) plastics by rating the
3、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 footnotes(excluding those
4、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 parentheses are given for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated w
5、ith 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 is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D883 Term
6、inology Relating to PlasticsD1600 Terminology for Abbreviated Terms Relating toPlastics3. Terminology3.1 GeneralDefinitions are in accordance with Terminol-ogy D883 and abbreviations with Terminology D1600, unlessotherwise indicated.4. Summary of Practice4.1 Test specimens of plasticized poly(vinyl
7、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, a specimen is removed, bent 360 in the opposit
8、edirection, and the former inside of the loop (now the outside)is examined for evidence of plasticizer spew.5. Significance and Use5.1 It is possible for plasticizers to become less compatiblein poly(vinyl chloride) resin when fused compound is sub-jected to compressive stress.5.1.1 This test subjec
9、ts a standard test specimen to a definitedeformation and allows qualitative determination of theamount of spew that is capable of occurring over a period oftime.5.1.2 An apparent decrease in compatibility of plasticizerswith subsequent exudation can cause excessive dirt pickup,marring of lacquered o
10、r 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, one way torelieve the stress is by migration of the plasticizer from thecompressed area (inside of bend) to the area in
11、 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 be reabsorb
12、ed. It is possible for certainplasticizers to spew and be reabsorbed quite rapidly. Lesscompatible plasticizers are capable of spewing early andcontinuing to spew throughout the test. A test of one weeksduration is used for screening, while an extended test of sevenweeks duration is used for a compl
13、ete profile.NOTE 3It is permissible for the seller and the purchaser to agree uponother test conditions of time, temperature, or relative humidity.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 responsib
14、ility of Subcommittee D20.15 on Thermoplastic Materials.Current edition approved Sept. 1, 2011. Published September 2011. Originallyapproved in 1974. Last previous edition approved in 2003 as D3291 97 (2003).DOI: 10.1520/D3291-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
15、orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
16、, 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) sheet 1.9 6 0.1 mm (0.075 60.005 in.) thick, taking care to ensure the lon
17、g 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. Conditioning8.1 Test specimens shall be conditioned at 23 6 2C (73.46 3.6F) and
18、50 6 10 % 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 thickness7.6 mm(0.300 in.)as shown in Fig. 2. Leave about 4.75 mm (316 in.)of
19、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.9.2 Specimen must be thoroughly fused to give meaningfulresults. Collapse of the loop is one indication of incompletefusion.9.3 Mark the time of starting
20、the test.9.4 Place the loop jig containing the specimens in thechamber at 23 6 2C (73.4 6 3.6F) and 50 6 10 % relativehumidity.9.5 Test individual specimens for 4 h, 24 h, and 7 days.9.6 At the end of the testing period, remove a specimenfrom the jig and fold the loop in the opposite direction aroun
21、dindex 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.9.7 Rate spew according to the appearance of the cigarettepaper immediately after wiping.9.8 Subj
22、ect those specimens which show exudation after the7-day test period to long-term testing by repeating 8.1-9.7.Start seven specimens together with examination of onespecimen each week for 7 weeks.10. Interpretation of Results10.1 Assign a rating in accordance with the following:3An example of a satis
23、factory 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-hardening precision ground tool and die steelFIG. 1 Bending Test
24、 JigD3291 112Description of Cigarette PaperAmount ofExudationGradingNo mark on paper or visible evidence in loop. none 0Oily mark on paper very faint and discontinu-ous.slight 1It is possible for the wetted area to appearsaturated in small spots, although much of itis not saturated.moderate 2Total w
25、etted 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 Bias412.1 ReproducibilityMultilaboratory test resul
26、ts 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 not been determined.13. Keywords13.1 plasticize
27、r compatibility; plasticizers; poly(vinylchloride)SUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D3291 97(2003) that may impact the use of this standard. (September 1, 2011)(1) Removed permissive language. (2) Updated conditioni
28、ng information.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 such patent rights, and the riskof infringement of s
29、uch 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. Your comments are invited either for revision of this standard or for add
30、itional 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 comments have not received a fair hearing you shouldmake your views known to t
31、he 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 th
32、e 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 ASTM website (www.astm.org/COPYRIGHT/).4Round-robin data for this practice are available from ASTM Headquarters.Request RR:D20-1037.FIG. 2 Perspective Drawing Showing Sample Mounted in JigD3291 113
