1、Designation: D5991 15D5991 17Standard 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 safety, health, and healthenvironmental practices
7、 and determine theapplicability of regulatory limitations prior to use. For specific hazards see Section 8.NOTE 3There is no known ISO equivalent to this standard.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in t
8、he Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1600 Terminology for Abbreviated Terms Relating to PlasticsD7209 Guide fo
9、r Waste Reduction, Resource Recovery, and 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 wi
10、th Terminology D1600 and Guide D7209. Units 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 Practic
11、e4.1 For the Beilstein Test, chlorine-containing 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.Curr
12、ent edition approved Oct. 1, 2015Dec. 1, 2017. Published October 2015January 2018. Originally approved in 1996. Last previous edition approved in 20092015 asD5991 - 09.D5991 - 15. DOI: 10.1520/D5991-15.10.1520/D5991-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactAS
13、TM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been mad
14、e 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 by ASTM is to be considered the official document.*A S
15、ummary 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 ultraviolet radiation. PET normally fluoresces with a blueor
16、 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. After a minimum of 45 min, the flakes arevisually exam
17、ined 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 flakes. Theseflakes are visually identified and subs
18、equently removed, and weighed. The identification of PVC flakes is confirmed with the flametest.4.5 With Procedure D, PET flakes are heated with an aqueous solution containing an optical brightener that also preferentiallystains the PVC flakes. The flakes are sorted under UV light in a dark room wit
19、h 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 results in equipment corrosion problems duringprocessing. The PVC contamination levelevel shall dictate the market for use of the recycled
20、polymer in secondary products.Procedures presented in this practice are used to identify the PVC contamination in recycled PET flakes.NOTE 4These procedures may also be used to estimate the concentration of PVC contamination.6. Apparatus6.1 Procedure A:6.1.1 Bright Aluminum Tray, shallow depth (0.75
21、 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 Circulating 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.
22、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, 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 devic
23、e.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 (Navy Blue #30), or equivalent, required for Procedure C.7.3 Rit Brightener and Whitener, or equivalent, required for Procedure D.8. Hazar
24、ds8.1 The ultraviolet light used in Procedures A and D is harmful to exposed skin and unprotected eyes, so a UV filtering faceshield or UV absorbing glasses shall be worn when performing this test. Exposed hands and arms shall be covered with glovesand long sleeves.8.2 Hot trays and flake samples sh
25、all be handled with thermally insulated gloves to avoid burns while placing trays containingsamples into or removing them from the oven (Procedure B).8.3 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
26、 sources.D5991 1729. Procedure9.1 Flame Test to Verify PVC Identification (Beilstein Test):9.1.1 Heat a copper wire in a propane torch flame 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 flam
27、e. 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 indicates that the test flake is not PVC.9.1.4 The flame test can give false positive PVC results if there is another halogenated material present in the PET. Brominat
28、edor chlorinated flame retardants or any additive with a halogen will give a positive color change with the flame test as indicated.NOTE 5CPVC, PVDC, brominated polystyrene, etc. are examples of materials that will give a false positive.9.2 Procedure A:9.2.1 Weigh 454 6 10 g of clean, dry PET flake
29、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 particles that do not exhibit the standard PET blue orviolet-blue color. Set the isolated flakes aside in
30、 a separate tray for subsequent weighing or testing in accordance with 9.1.NOTE 6Finding uniquely colored flakes under UV light should not be interpreted as fact that these particles are PVC. PVC can exhibit many colors(yellow/green, bright blue, dark violet, light orange) under UV light, and becaus
31、e of the blue colors exhibited by some PVC material, these flakes maynot be discernible from PET flakes under UV light.NOTE 7Clear PET fluoresces strongly emitting a blue to violet-blue color. Other PET products, however, have been observed to fluoresce with paleblue or clear, dark purple, or turquo
32、ise 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 8Paper, labels, and assorted pigmented plastics may also exhibit a spectrum of fluorescent colors or these materials may appear v
33、ery 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.9.3.3 Quickly place the tray containing the flake into the heated oven.9.3.4 After a minimum of 45 min
34、, remove the hot tray from the oven and place it on a suitable surface to cool to roomtemperature.NOTE 9If heating times are short, any PVC may not char completely and the discoloration may stop at a yellow-orange state that is typical of thecolor produced by similar heating of glue residues. The he
35、ating 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 on a clean, white surface. Using tweezers, sort through the flakes in the tray and remove anyblac
36、k, burnt pieces of plastic.NOTE 10Burnt, melted polyethylene or PET with blackened glue residues usually have a different physical appearance than PVC. The suspectedpresence of these contaminants will usually require testing by 9.1 to verify the presence of PVC.NOTE 11While placing wet flake into th
37、e 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 cooling effect.9.4 Procedure C:9.4.1 Transfer clean PET flake from 9.12 into a 3 to 4 L metal container
38、 by tapping the flake-filled strainer against the rim ofthe container.NOTE 12Since 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.9.4.2 Add 1.2 L of the blue acetone dye solution (10 % w/v) to the container to ensure coverage of a
39、ll 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 acetone/waterdye solution into an appropriate glass storage vessel and seal tightly.NOTE 13If the
40、 test square of PVC (Note 910) 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 transfer of the flake to the strainer, longer time will be required to carry out this test.NOTE 14T
41、he 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 water until there does not appear to be any blue liquid being rinsedfrom the flakes.9.4.5 Spread th
42、e 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 Air dry the isolated blue PVC flakes.9.5 Procedure D:9.5.1 Transfer clean PET flake into a 3 to 4 Lmetal container by
43、tapping the flake-filled strainer against the rim of the container.D5991 173NOTE 15Since 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.9.5.2 Add 1500 6 10 mL of water and 3.5 6 0.2 g of the Rit Brightener and Whitener to the cont
44、ainer. Bring the mixture toa boil on a hotplate.9.5.3 After boiling for a minimum of 30 min, skim off any paper floating on the surface. Then remove the container from thehotplate and pour the contents through a strainer.9.5.4 Rinse all remaining flakes into the strainer using additional tap water.9
45、.5.5 Immediately rinse 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.
46、9.5.7 Using tweezers, 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 16Pieces of label and PET with adhering glue residues will also glow blue, although
47、 PET with glue residue 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) (PE
48、T); poly(vinyl chloride) (PVC); recycled plasticsSUMMARY OF CHANGESCommittee D20 has identified the location of selected changes to this standard since the last issue(D5991 - 09D5991 - 15) that may impact the use of this standard. (October(December 1, 2015)2017)(1) Reworded 4.3, 4.4, 5.1, 8.1, 8.2,
49、9.3.4, 9.4.4, 9.4.6, 9.5.3, and 9.5.5.Section 2: Removed D7209 reference.(2) Added new Note 4 and renumbered all other notes.Subsection 3.1: Reworded/removed D7209 reference.(3) Removed Footnote 3.Section 5: Reworded; corrected spelling.(4) Added new 9.5.4.9.1.4 on false positive.(5) Removed oldAdded new Note 14.5.(6) Renumbered old 9.5.4Notes 6 9.5.615 to 9.5.57 9.5.7.16.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 advi
