1、Designation:D581418Standard Practice forDetermination of Contamination in Recycled Poly(EthyleneTerephthalate)(PET)Flakes and Chips Using a Plaque Test1This standard is issued under the fixed designation D5814;the number immediately following the designation indicates the year oforiginal adoption or
2、,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 covers an indication of the quality ofrecycled transparent poly(ethylen
3、e terephthalate)by examina-tion of a wafer or plaque formed by melting a representativesample and quenching it to prevent crystallization.1.2 Specific contaminants and impurities such as aluminumparticles,dirt particles,paper,and fibers are identified in thetransparent wafer.1.3 The overall color of
4、 the plaque is indicative of oxidiz-able contaminants such as ethylene-vinyl acetate(EVA)glueresidue and the number of bubbles present in the plaque givesan indication of the moisture content of the sample.1.4 UnitsThe values stated in SI units are to be regardedas standard.No other units of measure
5、ment are included in thisstandard.1.5 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,health,and environmental practices and deter-mine the applicability of regula
6、tory limitations prior to use.Specific precautionary statements are given in Section 8.NOTE1There is no known ISO equivalent to this standard.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Pri
7、nciples for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1600 Terminology forAbbreviated Terms Relating to Plas-ticsIEEE/ASTM SI 10 Standard for Use of
8、the InternationalSystem of Units(SI):The Modern Metric System3.Terminology3.1 DefinitionsThe terminology used in this practice is inaccordance with Terminology D1600.Units and symbols are inaccordance with IEEE/ASTM SI 10:Standard for Use of theInternational System of Units(SI).3.2 Definitions of Te
9、rms Specific to This Standard:3.2.1 plaquea transparent wafer resulting from meltingand rapid quenching of the polymer.4.Summary of Test Method4.1 Transparent poly(ethylene terephthalate)flakes aremelted in an aluminum pan,then the molten sample is rapidlyquenched in ice water to prevent crystalliza
10、tion.The resultingclear plaque is examined for color indicative of oxidizablecontaminants,bubbles indicative of moisture,and solid con-taminant particles.5.Significance and Use5.1 Presence of paper,metal,or incompatible polymercontamination in poly(ethylene terephthalate)renders the re-cycled polyme
11、r unfit for use in secondary product manufactur-ing operations.This procedure is useful for identifying differ-ent types of contamination in recycled PET flakes.6.Apparatus6.1 Oven,forced convection type capable of heatingsamples to 300C.6.2 Tongs,long arm.6.3 Stopwatch,0.1-s accuracy.6.4 Bucket,1 L
12、,stainless steel.6.5 Aluminum Weighing Dishes,57 mm diameter by 16 mmdeep(60 mL capacity).6.6 Thermally Insulated Gloves.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.95 on Recycled Plastics.Current edition approved Aug.
13、1,2018.Published September 2018.Originallyapproved in 1995.Last previous edition approved in 2010 as D5814 10.DOI:10.1520/D5814-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information
14、,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 StatesThis international standard was developed in accordance with i
15、nternationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 7.Materials7.1 Virgin Poly(ethylene terephthal
16、ate).7.2 Ice.7.3 Paper Towels.8.Hazards8.1 Always wear thermally insulated gloves when introduc-ing or removing the polymer sample from the oven.9.Procedure9.1 Preheat the oven to 275 6 5C and equilibrate for 30min.NOTE2Accuracy of both time and temperature is critical to validsample-to-sample comparisons using this test.9.2 Obtain three aluminum pans and label them“A,”“B,”and“C.”Weigh 5.5 6 0.1 g of sample into each of the pans.Tap each sample pan gently on a flat surface to evenly spreadthe ch
