ASTM D5991-96(2002)

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Designation: D 5991 – 96 (Reapproved 2002)
Standard Practice for
Separation and Identification of Poly(Vinyl Chloride) (PVC)
Contamination in Poly(Ethylene Terephthalate) (PET) Flake
This standard is issued under the fixed designation D 5991; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope (SI) (the Modernized Metric System)
1.1 This practice covers four procedures for separation and
3. Terminology
qualitative identification of poly(vinyl chloride) (PVC) con-
3.1 The terminology used in this practice is in accordance
tamination in poly(ethylene terephthalate) (PET) flakes.
with Terminology D 1600 and Guide D 5033. Units and
NOTE 1—Although not presented as a quantitative method, procedures
symbols are in accordance with Practice E 380.
presentedinthispracticemaybeusedtoprovidequantitativeresultsatthe
3.2 Definitions of Terms Specific to This Standard:
discretion of the user. The user assumes the responsibility to verify the
3.2.1 light material, n—paper, polymers such as polyethyl-
reproducibility of quantitative results. Data from an independent source
ene and polypropylene, and other materials with densities less
suggest a PVC detection level of 200 ppm (w/w) based on an original
than 1.00 g/cm .
sample weight of 454 g.
1.2 Procedure A is based on different fluorescence of PVC
4. Summary of Practice
and PET when these polymers are exposed to ultraviolet (UV)
4.1 For the Beilstein Test, chlorine-containing materials
light.
heated in a flame in contact with a copper wire produce a
1.3 Procedure B is an oven test based upon the charring of
characteristic green flame.
PVC when it is heated in air at 235°C.
4.2 With Procedure A, a known amount of PET flakes is
1.4 Procedures C and D are dye tests based on differential
exposed to ultraviolet radiation. PET normally fluoresces with
staining of PVC and PET.
a blue or violet color. Flakes fluorescing with different colors
NOTE 2—Other polymers (for example, PETG) also absorb the stain or
are removed, weighed, and identified as PVC if they burn with
brightener. Such interferences will result in false positive identification of
a bright green flame when heated on a copper wire.
PVC as the contaminant.
4.3 With Procedure B, PET flakes are heated in an oven
1.5 This standard does not purport to address all of the
maintained at 235 6 5°C.After 45 min, the flakes are visually
safety concerns, if any, associated with its use. It is the
examined with removal and subsequent weighing of black,
responsibility of the user of this standard to establish appro-
charred pieces. Pieces are confirmed as PVC using the same
priate safety and health practices and determine the applica-
flame test mentioned in 4.1.
bility of regulatory limitations prior to use.Forspecifichazards
4.4 With Procedure C, PET flakes are soaked in a blue
see Section 8.
acetone dye solution that preferentially stains any PVC flakes.
These flakes are visually identified and subsequently removed,
NOTE 3—There is no equivalent ISO standard.
and weighed. If desired, the identification of PVC flakes is
2. Referenced Documents confirmed with the flame test.
4.5 With Procedure D, PET flakes are heated with an
2.1 ASTM Standards:
aqueous solution containing an optical brightener that also
D 1600 Terminology for Abbreviated Terms Relating to
preferentiallystainsthePVCflakes.Theflakesaresortedunder
Plastics
UV light in a dark room with removal and subsequent
D 5033 GuidefortheDevelopmentofStandardsRelatingto
weighing of any blue fluorescing PVC flakes.
the Proper Use of Recycled Plastics
E 380 Practice for Use of the International System of Units
5. Significance and Use
5.1 Presence of even low concentrations of PVC in recycled
PET flakes may result in equipment corrosion problems during
ThispracticeisunderthejurisdictionofASTMCommitteeD20onPlasticsand
processing. The level of PVC contamination may also dictate
is the direct responsibility of Subcommittee D20.95 on Recycled Plastics.
Current edition approved July 10, 1996. Published September 1996.
2 3
Annual Book of ASTM Standards, Vol 08.03. Annual Book of ASTM Standards, Vol 14.02.
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D 5991 – 96 (2002)
the market for use of the recycled polymer in secondary 9.1.2 Touch the hot wire to a suspected PVC flake to melt a
products. Procedures presented in this practice are used to small amount of the flake on to the wire.
identify and, if desired, estimate the concentration of PVC 9.1.3 Reheat the wire tip in the flame. If the tested flake is
contamination in recycled PET flakes. PVC, a bright green flame will be visible as the wire heats and
the plastic burns. Absence of a green flame indicates that the
6. Apparatus
test flake is not PVC.
6.1 Procedure A: 9.2 Procedure A:
6.1.1 Bright Aluminum Tray, shallow depth (0.75 cm). 9.2.1 Weigh 454 6 10 g of clean, dry PET flake sample and
6.1.2 Light Fixture, equipped with GE F40/BLB, or equiva- transfer the sample into a shallow aluminum tray.
lent, black light bulbs. 9.2.2 Place the tray under the UV light in a dark environ-
6.1.3 Ultraviolet Shield Glasses. ment.
6.1.4 Tweezers. 9.2.3 Using tweezers, sort through the flakes in the tray and
6.2 Procedure B: remove all particles that do not exhibit the standard PET blue
6.2.1 Circulating or Forced-Air Oven, equipped with a or violet-blue color. Set the isolated flakes aside in a separate
temperature readout device for the range of 230 to 240°C. tray for subsequent weighing or testing in accordance with 9.1.
6.2.2 Baking Trays,14by20by3cm.
NOTE 4—Finding uniquely colored flakes under UV light should not be
6.2.3 Tweezers.
interpreted as fact that these particles are PVC. PVC can exhibit many
6.2.4 Thermally Insulated Gloves, or equivalent.
colors (yellow/green, bright blue, dark violet, light orange) under UV
6.3 Procedure C: light, and because of the blue colors exhibited by some PVC material,
these flakes may not be discernible from PET flakes under UV light.
6.3.1 Measuring Cup, 1.5 L.
NOTE 5—Clear PET fluoresces strongly emitting a blue to violet-blue
6.3.2 Plastic Stretch or Cling Wrap.
color. Other PETproducts, however, have been observed to fluoresce with
6.3.3 Paper Towels, newspaper, or equivalent.
pale blue or clear, dark purple, or turquoise colors. Green PET used for
6.3.4 Tweezers.
soft drink containers normally fluoresces from a bright to a dull green
6.4 Procedure D:
under UV light and amber PET flakes appear black under UV light.
6.4.1 Measuring Cup, 1.5 L.
NOTE 6—Paper, labels, and assorted pigmented plastics may also
6.4.2 Tweezers.
exhibit a spectrum of fluorescent colors or these materials may app
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