1、Designation: D5991 09D5991 15Standard Practice forSeparation and Identification of Poly(Vinyl Chloride) (PVC)Contamination in Poly(Ethylene Terephthalate) (PET) Flake1This standard is issued under the fixed designation D5991; the number immediately following the designation indicates the year oforig
2、inal 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 covers four procedures for separation and qualit
3、ative identification of poly(vinyl chloride) (PVC)contamination in poly(ethylene terephthalate) (PET) flakes.NOTE 1Although not presented as a quantitative method, procedures presented in this practice may be used to provide quantitative results at thediscretion of the user. The user assumes the res
4、ponsibility to verify the reproducibility of quantitative results. Data from an independent source suggesta PVC detection level of 200 ppm (w/w) based on an original sample weight of 454 g.1.2 Procedure A is based on different fluorescence of PVC and PET when these polymers are exposed to ultraviole
5、t (UV) light.1.3 Procedure B is an oven test based upon the charring of PVC when it is heated in air at 235C.1.4 Procedures C and D are dye tests based on differential staining of PVC and PET.NOTE 2Other polymers (for example, PETG) also absorb the stain or brightener. Such interferences will result
6、 in false positive identification of PVCas the contaminant.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabil
7、ity of regulatorylimitations prior to use. For specific hazards see Section 8.NOTE 3There is no known ISO equivalent to this practice.standard.2. Referenced Documents2.1 ASTM Standards:2D1600 Terminology for Abbreviated Terms Relating to PlasticsD7209 Guide for Waste Reduction, Resource Recovery, an
8、d Use of Recycled Polymeric Materials and Products (Withdrawn2015)3IEEE/ASTM SI-10 American National Standard for Use of the International System of Units (SI): The Modern Metric System3. Terminology3.1 The terminology used in this practice is in accordance with Terminology D1600 and Guide D7209. Un
9、its and symbols arein accordance with IEEE/ASTM SI-10.3.2 Definitions of Terms Specific to This Standard:3.2.1 light material, npaper, polymers such as polyethylene and polypropylene, and other materials with densities less than1.00 g/cm3.4. Summary of Practice4.1 For the Beilstein Test, chlorine-co
10、ntaining materials heated in a flame in contact with a copper wire produce a characteristicgreen flame.1 This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.95 on Recycled Plastics.Current edition approved Feb. 1, 2009Oct. 1,
11、 2015. Published February 2009October 2015. Originally approved in 1996. Last previous edition approved in 20022009 asD5991 - 96D5991 - 09.(2002). DOI: 10.1520/D5991-09.10.1520/D5991-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceast
12、m.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM
13、 standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published b
14、y ASTM is to be considered the official document.*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 States14.2 With Procedure A, a known amount of PET flakes is exposed to ultravi
15、olet radiation. PET normally fluoresces with a blueor violet color. Flakes fluorescing with different colors are removed, weighed, and identified as PVC if they burn with a brightgreen flame when heated on a copper wire.4.3 With Procedure B, PET flakes are heated in an oven maintained at 235 6 5C. A
16、fter a minimum of 45 min, the flakes arevisually examined with removal and subsequent weighing of black, charred pieces. Pieces are confirmed as PVC using the sameflame test mentioned in 4.1.4.4 With Procedure C, PET flakes are soaked in a blue acetone dye solution that preferentially stains any PVC
17、 flakes. Theseflakes are visually identified and subsequently removed, and weighed. If desired, the The identification of PVC flakes is confirmedwith the flame test.4.5 With Procedure D, PET flakes are heated with an aqueous solution containing an optical brightener that also preferentiallystains th
18、e PVC flakes. The flakes are sorted under UV light in a dark room with removal and subsequent weighing of any bluefluorescing PVC flakes.5. Significance and Use5.1 Presence of even low concentrations of PVC in recycled PET flakes may result results in equipment corrosion problemsduring processing. T
19、he level of PVC contamination may alsoleve shall dictate the market for use of the recycled polymer insecondary products. Procedures presented in this practice are used to identify and, if desired, estimate the concentration of the PVCcontamination in recycled PET flakes.NOTE 4These procedures may a
20、lso be used to estimate the concentration of PVC contamination.6. Apparatus6.1 Procedure A:6.1.1 Bright Aluminum Tray, shallow depth (0.75 cm).6.1.2 Light Fixture, equipped with GE F40/BLB, or equivalent, black light bulbs.6.1.3 Ultraviolet Shield Glasses.6.1.4 Tweezers.6.2 Procedure B:6.2.1 Circula
21、ting or Forced-Air Oven, equipped with a temperature readout device for the range of 230 to 240C.6.2.2 Baking Trays, 14 by 20 by 3 cm.6.2.3 Tweezers.6.2.4 Thermally Insulated Gloves, or equivalent.6.3 Procedure C:6.3.1 Measuring Cup, 1.5 L.6.3.2 Plastic Stretch or Cling Wrap.6.3.3 Paper Towels, news
22、paper, or equivalent.6.3.4 Tweezers.6.4 Procedure D:6.4.1 Measuring Cup, 1.5 L.6.4.2 Tweezers.6.4.3 Hot Plate, or equivalent heating device.6.4.4 Light Fixture, equipped with GE F40/BLB, or equivalent, black light bulbs.6.4.5 Ultraviolet Shield Glasses.7. Materials7.1 Detergent.7.2 Rit Tint and Dye
23、(Navy Blue #30), or equivalent, required for Procedure C.7.3 Rit Brightener and Whitener, or equivalent, required for Procedure D.8. Hazards8.1 The ultraviolet light used in ProceduresAand D may be is harmful to exposed skin and unprotected eyes, so a UV filteringface shield or UV absorbing glasses
24、shouldshall be worn when performing this test. Exposed hands and arms shouldshall becovered with gloves and long sleeves.8.2 Hot trays and flake samples shouldshall be handled with thermally insulated gloves to avoid burns while placing trayscontaining samples into or removing them from the oven (Pr
25、ocedure B).D5991 1528.3 Acetone used to prepare the dye solution for Procedure C is flammable. Use this reagent only in a well ventilated area freeof open flames or spark sources.9. Procedure9.1 Flame Test to Verify PVC Identification (Beilstein Test):9.1.1 Heat a copper wire in a propane torch flam
26、e until it is very hot.9.1.2 Touch the hot wire to a suspected PVC flake to melt a small amount of the flake on to the wire.9.1.3 Reheat the wire tip in the flame. If the tested flake is PVC, a bright green flame will be visible as the wire heats and theplastic burns. Absence of a green flame indica
27、tes that the test flake is not PVC.9.2 Procedure A:9.2.1 Weigh 454 6 10 g of clean, dry PET flake sample and transfer the sample into a shallow aluminum tray.9.2.2 Place the tray under the UV light in a dark environment.9.2.3 Using tweezers, sort through the flakes in the tray and remove all particl
28、es that do not exhibit the standard PET blue orviolet-blue color. Set the isolated flakes aside in a separate tray for subsequent weighing or testing in accordance with 9.1.NOTE 5Finding uniquely colored flakes under UV light should not be interpreted as fact that these particles are PVC. PVC can ex
29、hibit many colors(yellow/green, bright blue, dark violet, light orange) under UV light, and because of the blue colors exhibited by some PVC material, these flakes maynot be discernible from PET flakes under UV light.NOTE 6Clear PET fluoresces strongly emitting a blue to violet-blue color. Other PET
30、 products, however, have been observed to fluoresce with paleblue or clear, dark purple, or turquoise colors. Green PET used for soft drink containers normally fluoresces from a bright to a dull green under UV lightand amber PET flakes appear black under UV light.NOTE 7Paper, labels, and assorted pi
31、gmented plastics may also exhibit a spectrum of fluorescent colors or these materials may appear very dark underUV light.9.3 Procedure B:9.3.1 Weigh 454 6 10 g of clean, dry PET flake sample and transfer the sample into a baking tray.9.3.2 Adjust and equilibrate the oven temperature to 235 6 5C.9.3.
32、3 Quickly place the tray containing the flake into the heated oven.9.3.4 After a minimum of 45 min, remove the hot tray from the oven and place it on a suitable surface to cool to roomtemperature.NOTE 8If heating times are short, any PVC may not char completely and the discoloration may stop at a ye
33、llow-orange state that is typical of thecolor produced by similar heating of glue residues. The heating time must be sufficient to totally blacken any PVC flakes. Flakes in the center of a moundof PET flakes may degrade at a slower rate than material on the surface.9.3.5 Spread the cool, baked flake
34、 on a clean, white surface. Using tweezers, sort through the flakes in the tray and remove anyblack, burnt pieces of plastic.NOTE 9Burnt, melted polyethylene or PET with blackened glue residues usually have a different physical appearance than PVC. The suspectedpresence of these contaminants will us
35、ually require testing by 9.1 to verify the presence of PVC.NOTE 10While placing wet flake into the high temperature oven is possible, the moisture will tend to keep the flake cooler for a longer period oftime. Consequently, heating times longer than 45 min may be needed to compensate for this coolin
36、g effect.9.4 Procedure C:9.4.1 Transfer clean PET flake from 9.12 into a 3 to 4 L metal container by tapping the flake-filled strainer against the rim ofthe container.NOTE 11Since it is a good practice to run a standard with any test, add a 1.54 cm square piece of known PVC to the unknown flakes.9.4
37、.2 Add 1.2 L of the blue acetone dye solution (10 % w/v) to the container to ensure coverage of all of the flakes with thesolution. Cover the container tightly with plastic stretch wrap.9.4.3 Soak the flake for 15 to 20 min, then pour the blue flake and dye solution through a strainer. Transfer the
38、acetone/waterdye solution into an appropriate glass storage vessel and seal tightly.NOTE 12If the test square of PVC (Note 89) does not stain a very dark blue, the blue dye solution may no longer be usable and it should be replaced.As acetone evaporates from an uncovered container or loss during tra
39、nsfer of the flake to the strainer, longer time will be required to carry out this test.NOTE 13The blue acetone/water dye solution should be reused as many times as possible. Add small amounts of 50:50 acetone:water to replenishlost liquid.9.4.4 Immediately rinse the dyed flake under running tap wat
40、er until there does not appear to be any blue liquid being rinsedfrom the flakes.9.4.5 Spread the washed flake on white paper towels or a clean, white surface. Using tweezers, sort through the flakes in thetray and remove any uniformly dark blue stained pieces of plastic.9.4.6 Allow Air dry the isol
41、ated blue PVC flakes to air dry.flakes.9.5 Procedure D:9.5.1 Transfer clean PET flake into a 3 to 4 Lmetal container by tapping the flake-filled strainer against the rim of the container.D5991 153NOTE 14Since it is a good practice to run a standard with any test, add a 1.54 cm square piece of known
42、PVC to the unknown flakes.9.5.2 Add 1500 6 10 mL of water and 3.5 6 0.2 g of the Rit Brightener and Whitener to the container. Bring the mixture toa boil on a hotplate.9.5.3 After boiling for 30 min, a minimum of 30 min, skim off any paper floating on the surface. Then remove the containerfrom the h
43、otplate and pour the contents through a strainer. Rinse all remaining flakes into the strainer using additional water.NOTE 14Additional paper floating on the surface may also be skimmed off at this time.9.5.4 Rinse all remaining flakes into the strainer using additional tap water.9.5.5 Immediately r
44、inse the dyed flake under running tap water to cool it down and rinse off any remaining optical brightenersolution.9.5.6 Transfer the flake from the strainer to a shallow aluminum pan making sure not to lose any of the flakes. Place the trayunder the UV light in a dark environment.9.5.7 Using tweeze
45、rs, sort through the flakes in the tray and remove all particles that glow bright blue. Set the isolated flakesaside in a separate tray for subsequent weighing or testing in accordance with 9.1.NOTE 15Pieces of label and PET with adhering glue residues will also glow blue, although PET with glue res
46、idue will not show the intense bluefluorescence observed for PVC. Flimsy pieces of label are quickly identified from the rigid PVC flake.10. Report10.1 Report the test procedure used to isolate and identify PVC flakes.11. Keywords11.1 contamination; poly(ethylene terephthalate) (PET); poly(vinyl chl
47、oride) (PVC); recycled plasticsSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D5991 - 96D5991 - 09(2002) that may impact the use of this standard. (February(October 1, 2009)2015)(1) Updated ISO equivalency statement in accordance
48、 withReworded 4.3, 4.4, 5.1, 8.1, 8.2, 9.3.4, D4968.9.4.4, 9.4.6, 9.5.3, and9.5.5.(2) Referenced DocumentsDeletedAdded new D5033 reference.AddedNote 4 and D7209 reference.renumbered all other notes.(3) TerminologyReplacedRemoved D5033 reference with Footnote 3.D7209.(4) Added new 9.5.4.(5) Removed o
49、ld Note 14.(6) Renumbered old 9.5.4 9.5.6 to 9.5.5 9.5.7.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 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 not revised, either reapproved or
