ASTM_D_3291_-_11.pdf

Designation:D329111Standard 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,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 practice determines the compatibility of plasticiz-ers in poly(vinyl chloride)plastics by rating the amount ofplasticizer that spews due to compressional stress set up insidea 180 loop bend.NOTE1Ingredients 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 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 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.NOTE2There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-tics3.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 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 oppositedirection,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 subjects 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 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,one way torelieve the stress is by migration of the plasticizer from thecompressed area(inside of bend)to the 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 be reabsorbed.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 complete profile.NOTE3It 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 responsibility 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,orcontact ASTM Customer 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 19428-2959.United States1 6.2 Cigarette Papers,cut in half to be approximatelysquare.37.Specimen Preparation7.1 Cut test specimens 12.7 by 25.4 mm(12by 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 long edges areparallel.NOTE4Optimum 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