1、Designation: D 5991 09Standard Practice forSeparation and Identification of Poly(Vinyl Chloride) (PVC)Contamination in Poly(Ethylene Terephthalate) (PET) Flake1This standard is issued under the fixed designation D 5991; the number immediately following the designation indicates the year oforiginal a
2、doption 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 andqualitative i
3、dentification of poly(vinyl chloride) (PVC) con-tamination in poly(ethylene terephthalate) (PET) flakes.NOTE 1Although not presented as a quantitative method, procedurespresented in this practice may be used to provide quantitative results at thediscretion of the user. The user assumes the responsib
4、ility to verify thereproducibility of quantitative results. Data from an independent sourcesuggest a PVC detection level of 200 ppm (w/w) based on an originalsample weight of 454 g.1.2 Procedure A is based on different fluorescence of PVCand PET when these polymers are exposed to ultraviolet (UV)lig
5、ht.1.3 Procedure B is an oven test based upon the charring ofPVC when it is heated in air at 235C.1.4 Procedures C and D are dye tests based on differentialstaining of PVC and PET.NOTE 2Other polymers (for example, PETG) also absorb the stain orbrightener. Such interferences will result in false pos
6、itive identification ofPVC as the contaminant.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 and health practices and determine the applica-bility of regul
7、atory limitations prior to use. For specific hazardssee Section 8.NOTE 3There is no known ISO equivalent to this practice.2. Referenced Documents2.1 ASTM Standards:2D 1600 Terminology for Abbreviated Terms Relating toPlasticsD 7209 Guide for Waste Reduction, Resource Recovery,and Use of Recycled Pol
8、ymeric Materials and ProductsIEEE/ASTM SI-10 American National Standard for Use ofthe International System of Units (SI): The Modern MetricSystem3. Terminology3.1 The terminology used in this practice is in accordancewith Terminology D 1600 and Guide D 7209. Units andsymbols are in accordance with I
9、EEE/ASTM SI-10.3.2 Definitions of Terms Specific to This Standard:3.2.1 light material, npaper, polymers such as polyethyl-ene and polypropylene, and other materials with densities lessthan 1.00 g/cm3.4. Summary of Practice4.1 For the Beilstein Test, chlorine-containing materialsheated in a flame in
10、 contact with a copper wire produce acharacteristic green flame.4.2 With Procedure A, a known amount of PET flakes isexposed to ultraviolet radiation. PET normally fluoresces witha blue or violet color. Flakes fluorescing with different colorsare removed, weighed, and identified as PVC if they burn
11、witha bright green flame when heated on a copper wire.4.3 With Procedure B, PET flakes are heated in an ovenmaintained at 235 6 5C. After 45 min, the flakes are visuallyexamined with removal and subsequent weighing of black,charred pieces. Pieces are confirmed as PVC using the sameflame test mention
12、ed in 4.1.4.4 With Procedure C, PET flakes are soaked in a blueacetone dye solution that preferentially stains any PVC flakes.These flakes are visually identified and subsequently removed,and weighed. If desired, the identification of PVC flakes isconfirmed with the flame test.4.5 With Procedure D,
13、PET flakes are heated with anaqueous solution containing an optical brightener that alsopreferentially stains the PVC flakes. The flakes are sorted underUV light in a dark room with removal and subsequentweighing of any blue fluorescing PVC flakes.5. Significance and Use5.1 Presence of even low conc
14、entrations of PVC in recycledPET flakes may result in equipment corrosion problems duringprocessing. The level of PVC contamination may also dictate1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.95 on Recycled Plastics.Cu
15、rrent edition approved Feb. 1, 2009. Published February 2009. Originallyapproved in 1996. Last previous edition approved in 2002 as D 5991 - 96(2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
16、ards 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, West Conshohocken, PA 19428-2959, United States.the market for use of the recy
17、cled polymer in secondaryproducts. Procedures presented in this practice are used toidentify and, if desired, estimate the concentration of PVCcontamination in recycled PET flakes.6. Apparatus6.1 Procedure A:6.1.1 Bright Aluminum Tray, shallow depth (0.75 cm).6.1.2 Light Fixture, equipped with GE F4
18、0/BLB, or equiva-lent, black light bulbs.6.1.3 Ultraviolet Shield Glasses.6.1.4 Tweezers.6.2 Procedure B:6.2.1 Circulating or Forced-Air Oven, equipped with atemperature readout device for the range of 230 to 240C.6.2.2 Baking Trays,14by20by3cm.6.2.3 Tweezers.6.2.4 Thermally Insulated Gloves, or equ
19、ivalent.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, newspaper, 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
20、 equiva-lent, black light bulbs.6.4.5 Ultraviolet Shield Glasses.7. Materials7.1 Detergent.7.2 Rit Tint and Dye (Navy Blue #30),3or equivalent,required for Procedure C.7.3 Rit Brightener and Whitener,3or equivalent, required forProcedure D.8. Hazards8.1 The ultraviolet light used in Procedures A and
21、 D may beharmful to exposed skin and unprotected eyes, so a UV filteringface shield or UV absorbing glasses should be worn whenperforming this test. Exposed hands and arms should becovered with gloves and long sleeves.8.2 Hot trays and flake samples should be handled withthermally insulated gloves t
22、o avoid burns while placing trayscontaining samples into or removing them from the oven(Procedure B).8.3 Acetone used to prepare the dye solution for ProcedureC is flammable. Use this reagent only in a well ventilated areafree of open flames or spark sources.9. Procedure9.1 Flame Test to Verify PVC
23、Identification (Beilstein Test):9.1.1 Heat a copper wire in a propane torch flame until it isvery hot.9.1.2 Touch the hot wire to a suspected PVC flake to melt asmall amount of the flake on to the wire.9.1.3 Reheat the wire tip in the flame. If the tested flake isPVC, a bright green flame will be vi
24、sible as the wire heats andthe plastic burns. Absence of a green flame indicates that thetest flake is not PVC.9.2 Procedure A:9.2.1 Weigh 454 6 10 g of clean, dry PET flake sample andtransfer the sample into a shallow aluminum tray.9.2.2 Place the tray under the UV light in a dark environ-ment.9.2.
25、3 Using tweezers, sort through the flakes in the tray andremove all particles that do not exhibit the standard PET blueor violet-blue color. Set the isolated flakes aside in a separatetray for subsequent weighing or testing in accordance with 9.1.NOTE 4Finding uniquely colored flakes under UV light
26、should not beinterpreted as fact that these particles are PVC. PVC can exhibit manycolors (yellow/green, bright blue, dark violet, light orange) under UVlight, and because of the blue colors exhibited by some PVC material,these flakes may not be discernible from PET flakes under UV light.NOTE 5Clear
27、 PET fluoresces strongly emitting a blue to violet-bluecolor. Other PET products, however, have been observed to fluoresce withpale blue or clear, dark purple, or turquoise colors. Green PET used forsoft drink containers normally fluoresces from a bright to a dull greenunder UV light and amber PET f
28、lakes appear black under UV light.NOTE 6Paper, labels, and assorted pigmented plastics may alsoexhibit a spectrum of fluorescent colors or these materials may appearvery dark under UV light.9.3 Procedure B:9.3.1 Weigh 454 6 10 g of clean, dry PET flake sample andtransfer the sample into a baking tra
29、y.9.3.2 Adjust and equilibrate the oven temperature to 235 65C.9.3.3 Quickly place the tray containing the flake into theheated oven.9.3.4 After 45 min, remove the hot tray from the oven andplace it on a suitable surface to cool to room temperature.NOTE 7If heating times are short, any PVC may not c
30、har completelyand the discoloration may stop at a yellow-orange state that is typical ofthe color produced by similar heating of glue residues. The heating timemust be sufficient to totally blacken any PVC flakes. Flakes in the centerof a mound of PET flakes may degrade at a slower rate than materia
31、l onthe surface.9.3.5 Spread the cool, baked flake on a clean, white surface.Using tweezers, sort through the flakes in the tray and removeany black, burnt pieces of plastic.NOTE 8Burnt, melted polyethylene or PET with blackened glueresidues usually have a different physical appearance than PVC. The
32、suspected presence of these contaminants will usually require testing by9.1 to verify the presence of PVC.NOTE 9While placing wet flake into the high temperature oven ispossible, the moisture will tend to keep the flake cooler for a longer periodof time. Consequently, heating times longer than 45 mi
33、n may be neededto compensate for this cooling effect.9.4 Procedure C:9.4.1 Transfer clean PET flake from 9.12 intoa3to4Lmetal container by tapping the flake-filled strainer against therim of the container.3The sole source of supply of the apparatus known to the committee at this timeis CPC Specialty
34、 Products, Indianapolis, IN. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.D5991092NOTE 10Since it is a good practi
35、ce to run a standard with any test, adda 1.54 cm square piece of known PVC to the unknown flakes.9.4.2 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
36、flake for 15 to 20 min, then pour the blueflake and dye solution through a strainer. Transfer the acetone/water dye solution into an appropriate glass storage vessel andseal tightly.NOTE 11If the test square of PVC (Note 8) does not stain a very darkblue, the blue dye solution may no longer be usabl
37、e and it should bereplaced. As acetone evaporates from an uncovered container or lossduring transfer of the flake to the strainer, longer time will be required tocarry out this test.NOTE 12The blue acetone/water dye solution should be reused asmany times as possible. Add small amounts of 50:50 aceto
38、ne:water toreplenish lost liquid.9.4.4 Immediately rinse the dyed flake under running wateruntil 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 aclean, white surface. Using tweezers, sort through the flakes inthe tray an
39、d remove any uniformly dark blue stained pieces ofplastic.9.4.6 Allow the isolated blue PVC flakes to air dry.9.5 Procedure D:9.5.1 Transfer clean PET flake intoa3to4Lmetalcontainer by tapping the flake-filled strainer against the rim ofthe container.NOTE 13Since it is a good practice to run a stand
40、ard with any test, adda 1.54 cm square piece of known PVC to the unknown flakes.9.5.2 Add 1500 6 10 mL of water and 3.5 6 0.2 g of the RitBrightener and Whitener to the container. Bring the mixture toa boil on a hotplate.9.5.3 After boiling for 30 min, remove the container fromthe hotplate and pour
41、the contents through a strainer. Rinse allremaining flakes into the strainer using additional water.NOTE 14Additional paper floating on the surface may also beskimmed off at this time.9.5.4 Immediately rinse the dyed flake under running waterto cool it down and rinse off any remaining optical bright
42、enersolution.9.5.5 Transfer the flake from the strainer to a shallowaluminum pan making sure not to lose any of the flakes. Placethe tray under the UV light in a dark environment.9.5.6 Using tweezers, sort through the flakes in the tray andremove all particles that glow bright blue. Set the isolated
43、flakes aside in a separate tray for subsequent weighing ortesting in accordance with 9.1.NOTE 15Pieces of label and PET with adhering glue residues willalso glow blue, although PET with glue residue will not show the intenseblue fluorescence observed for PVC. Flimsy pieces of label are quicklyidenti
44、fied from the rigid PVC flake.10. Report10.1 Report the test procedure used to isolate and identifyPVC flakes.11. Keywords11.1 contamination; poly(ethylene terephthalate) (PET);poly(vinyl chloride) (PVC); recycled plasticsSUMMARY OF CHANGESCommittee D20 has identified the location of selected change
45、s to this standard since the last issue(D 5991 - 96(2002) that may impact the use of this standard. (February 1, 2009)(1) Updated ISO equivalency statement in accordance withD 4968.(2) Referenced DocumentsDeleted D 5033 reference.Added D 7209 reference.(3) TerminologyReplaced D 5033 reference with D
46、 7209.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 right
47、s, 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 additional s
48、tandardsand 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 the ASTM C
49、ommittee 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 the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D5991093
