1、Designation: D5814 18Standard 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 adopti
2、on 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 covers an indication of the quality ofrecycled transparent
3、poly(ethylene 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
4、overall color of 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 oth
5、er units of measurement 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
6、 applicability of regulatory limitations prior to use.Specific precautionary statements are given in Section 8.NOTE 1There 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 establish
7、ed in the Decision on Principles 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/AS
8、TM SI 10 Standard for Use of 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
9、of Units (SI).3.2 Definitions of Terms 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 rapidlyquench
10、ed in ice water to prevent crystallization. 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(ethylen
11、e terephthalate) renders the re-cycled polymer 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, lon
12、g arm.6.3 Stopwatch, 0.1-s accuracy.6.4 Bucket, 1 L, 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
13、.95 on Recycled Plastics.Current edition approved Aug. 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 servi
14、ceastm.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
15、 StatesThis international standard was developed in accordance with internationally 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 t
16、o Trade (TBT) Committee.17. Materials7.1 Virgin Poly(ethylene terephthalate).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.NOTE 2Accur
17、acy 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 chips.9.3 Weigh 5.5 6
18、0.1 g of virgin PET into another pan.9.4 Quickly open the oven door, place the pans in the centerof the oven, and close the oven door to minimize heat loss. Itis important that this step take place as quickly, efficiently, andreproducibly as possible.9.5 Start the stopwatch as soon as the oven tempe
19、raturerecovers and stabilizes at 275C. After 2 min, record the oventemperature (that should be 275C).9.6 Prepare an ice water bath by filling the 1-L bucket withcold tap water. Add ice and decant off some of the water tomaintain a 5-cm floating ice level on the surface of the water.The bucket should
20、 be about 90 % full with the ice and waterslurry. Place the bucket with the ice slurry as close to the ovenas possible.9.7 At 10.00 min on the stopwatch, quickly remove thesamples from the oven with the tongs and immediatelysubmerge them into the ice bath. This rapid quenching preventscrystallizatio
21、n of the PET.9.8 Remove the pans from the ice bath and blot dry withpaper towels. Remove the hardened plastic disks formed in theoven (plaques) from the aluminum pans by peeling the pansfrom the plaques. Label each plaque with the “A,” “B,” or “C”designation earlier assigned to each sample.9.9 Place
22、 the plaques on a white background. Compare thesample and virgin PET plaques with respect to color, numberand description of particles, and the number of bubbles.10. Report10.1 Report the following information:10.1.1 The sample plaque color,10.1.2 The number and description of particles in thesample
23、 plaques, and10.1.3 The number of bubbles in the sample plaques.11. Keywords11.1 contamination; plaque test; poly(ethylene terephtha-late); recycled plasticSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue (D5814 - 10)that may impac
24、t the use of this standard. (August 1, 2018)(1) Section 2: Deleted D5033 reference.(2) Subsection 3.1: Reworded, deleted D5033 reference.(3) Subsection 6.5: Added dish capacity (new), removed foot-note 4.ASTM International takes no position respecting the validity of any patent rights asserted in co
25、nnection 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 such rights, are entirely their own responsibility.This standard is subject to revision at any time by the respo
26、nsible 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 additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful
27、 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 the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International,
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