1、Designation: D5577 94 (Reapproved 2010)1Standard Guide forTechniques to Separate and Identify Contaminants inRecycled Plastics1This standard is issued under the fixed designation D5577; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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.1NOTEReapproved with editorial change to Note 1 in January 2010.1. Scope1.1 This guide is intended to provide infor
3、mation on avail-able methods for the separation and classification of contami-nants such as moisture, incompatible polymers, metals, adhe-sives, glass, paper, wood, chemicals, and original-productresidues in recycled plastic flakes or pellets. Although nospecific methods for identification or charac
4、terization of foamproducts are included, foam products are not excluded fromthis guide. The methods presented apply to post-consumerplastics.1.2 For specific procedures existing as ASTM test methods,this guide only lists the appropriate reference. Where nocurrent ASTM standard exists, however, this
5、guide givesprocedures for the separation or identification, or both, ofspecific contaminants. Appendix X1 lists the tests and thespecific contaminant addressed by each procedure.1.3 This guide does not include procedures to quantify thecontaminants unless this information is available in referencedA
6、STM standards.1.4 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 regulatory limitations prior to use.N
7、OTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D789 Test Methods for Determination of Solution Viscosi-ties of Polyamide (PA)D792 Test Methods for Density and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD883 Terminology Relating
8、to PlasticsD1003 Test Method for Haze and Luminous Transmittanceof Transparent PlasticsD1193 Specification for Reagent WaterD1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion PlastometerD1457 Specification for Polytetrafluoroethylene (PTFE)Molding and Extrusion Materials3 2D1505 Tes
9、t Method for Density of Plastics by the Density-Gradient TechniqueD1898 Practice for Sampling of Plastics3D1925 Test Method for Yellowness Index of Plastics3D3418 Test Method for Transition Temperatures and En-thalpies of Fusion and Crystallization of Polymers byDifferential Scanning CalorimetryD401
10、9 Test Method for Moisture in Plastics by CoulometricRegeneration of Phosphorus Pentoxide3D5033 Guide for Development of ASTM Standards Relat-ing to Recycling and Use of Recycled Plastics3D5227 Test Method for Measurement of Hexane Extract-able Content of PolyolefinsE169 Practices for General Techni
11、ques of Ultraviolet-Visible Quantitative AnalysisE355 Practice for Gas Chromatography Terms and Rela-tionshipsE682 Practice for Liquid Chromatography Terms and Rela-tionshipsE794 Test Method for Melting And Crystallization Tem-peratures By Thermal AnalysisE1252 Practice for General Techniques for Ob
12、taining Infra-red Spectra for Qualitative Analysis1This guide is under the jurisdiction of ASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.95 on Recycled Plastics.Current edition approved Jan. 1, 2010. Published February 2010. Originallyapproved in 1994. Last previ
13、ous edition approved in 2003 as D5577 - 94(2003).DOI: 10.1520/D5577-94R10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe
14、ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.2 ISO Standards:4ISO 3451/1-1981 PlasticsDetermination of Ash; Part 1:General MethodsISO 1183-1987 Methods for Determining the Density andRelative Density of N
15、oncellular Plastics3. Terminology3.1 This terminology used in this guide is in accordancewith Terminology D883 and Guide D5033.3.2 Definitions of Terms Specific to This Standard:3.2.1 chemicalsnonhazardous or hazardous materials (forexample, insecticides or herbicides) potentially used in contactwit
16、h plastic materials.3.2.2 glueadhesives used for labels or joining bottle parts(for example, ethylene-vinyl acetate).3.2.3 heavy metalsmetals heavier than sodium on theperiodic table (for example, lead, arsenic, cadmium, chro-mium, or copper).3.2.4 heavy plasticunfilled polymers such as polystyrene,
17、poly(ethylene terephthalate), and poly(vinyl chloride) andfilled materials with densities greater than 1.00 g/cm3.3.2.5 light plasticpolymers such as polyethylene andpolypropylene with densities less than 1.00 g/cm3.3.2.6 original-product residuesresidues from anyoriginal-product contents of a plast
18、ic package (for example,milk, juice, or detergent).3.2.7 particlespiece of metal, glass, wood, paper, or otherdiscreetly shaped material equal to or larger than 0.1 mm2.3.2.8 specksany material equal to or less than 0.1 mm2.4. Summary of Guide4.1 This guide provides details of several procedures use
19、d toseparate and classify contaminants including, but not limitedto, moisture, original product residues, incompatible plastic,metal, paper, glass, adhesives, and wood in recycled plasticflakes or pellets. This guide lists existing ASTM and ISOmethods that can be used to characterize solid and some
20、liquidcontaminants. In addition, this guide presents details of someindustry procedures for identification of contaminants. Appen-dix X1 provides information on quantitative aspects of some ofthese industry standards that can also be used to estimate theconcentration of various contaminants.5. Signi
21、ficance and Use5.1 Recycled plastic materials may contain incompatibleplastic or other undesirable contaminants that could affect theprocessing or quality, or both, of the plastic prepared for reuse.Techniques to separate and identify incompatible plastics,moisture, chemicals, or original product re
22、sidues, and solidcontaminants such as metals, paper, glass, and wood areessential to the processing of recycled plastic materials.5.2 This guide lists existing ASTM and ISO methods pluscurrently practiced industrial techniques for identification andclassification of contaminants in recycled plastics
23、 flake orpellets.6. Sampling6.1 Unless otherwise stated, materials should be sampled inaccordance with the procedures described in Practice D1898.Adequate statistical sampling should be considered as anacceptable alternative.7. Existing ASTM or ISO Procedures7.1 Moisture:7.1.1 A coulometric method (
24、Test Method D4019), thestandard test method for haze (Test Method D1003), KarlFisher titration (Test Method D789), or a gravimetric proce-dure (13.6.1 of Specification D1457) can be used to estimatethe moisture content of recycled plastic materials.7.2 Visual Inspection and Product Uniformity:7.2.1
25、Color:7.2.1.1 Test Method D1925 measures the yellowness indexof clear acrylic plastics and the haze and the luminoustransmittance procedure (Test Method D1003) characterizesthe color of transparent unpigmented recycled plastic materi-als. These tests are not readily applied to pigmented plasticsampl
26、es.NOTE 2Test Method D1925 is currently being revised by ASTMSubcommittee D20.40 to address reproducibility and bias problems.7.2.2 Melt Flow for Product UniformityUniformity ofsome recycled plastic flakes or pellets can be estimated bymeasuring the flow rate of the material using an extrusionplasto
27、meter (Test Method D1238).7.3 Density or Specific GravityThe displacement methodfor specific gravity or relative density (Test Method D792)orthe density-gradient procedure for density (Test MethodD1505) are useful techniques to determine contamination ofrecycled plastic flakes or pellet samples with
28、 one or more otherpolymers.NOTE 3Test Method D1505 uses relatively small test specimens, so itmay not be applicable for analysis of nonhomogeneous recycled plasticmaterials.7.4 Inorganic Contaminants:7.4.1 An ash test, such as ISO 3451/1, or the muffle-furnacetechniques currently being evaluated wit
29、hin ASTM Subcom-mittee D20.70 (project designation X70-8702) can be used toestimate the inorganic filler content of recycled plastic flake orpellets.NOTE 4Some volatile metals may be lost using the test indicated in7.4.1. ASTM Subcommittee D20.70 is currently developing a test method(project X70-920
30、1) for metals, including heavy metals, that will includesample-preparation techniques to minimize the loss of volatile metalsprior to analysis by X-ray fluorescence or spectroscopic techniques.7.4.2 Ferrous (iron) contaminants can be removed with amagnet and aluminum contaminants are separated from
31、plasticmaterials using density procedures in accordance with 8.3.7.5 Thermal Analysis:7.5.1 Since most polymers exhibit unique temperatures formelting or other phase transitions, measurement of thesetransition temperatures (Test Method D3418) or the meltingand crystallization temperatures (Test Meth
32、od E794)ofasample may provide useful information regarding the identityof polymeric components present in a recycled plastic material.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.D5577 94 (2010)127.5.2 Both Test Method
33、s D3418 and E794 involve thermalgravimetric analysis (TGA) or differential scanning calorim-etry (DSC). These techniques utilize small samples (5 to 15mg), so they may not be practical for use in characterization ofpotentially nonhomogeneous recycled plastic materials.7.6 Infrared AnalysisQualitativ
34、e infrared analysis usingthe techniques of Practice E1252 can be used to identifypolymeric, chemical, and, in some cases, inorganic compo-nents of recycled plastic materials. Sample size considerationsindicated in 7.5.2 may also apply to preparation of samples forinfrared analysis.7.7 Chromatographi
35、c AnalysisThe principles of gas chro-matography, described in Practice E355, and liquid chroma-tography, described in Practice E682, are useful for separationand classification of chemical contaminants or residues fromoriginal-use contents of plastic packages.8. Additional Industrial Procedures8.1 S
36、pecimen Preparation:8.1.1 Using standard injection molding equipment, preparehomogenized sample plaques.8.1.2 Plaques, or slices from plaques prepared in 8.1.1, canbe used for differential scanning calorimetry (DSC), infraredanalysis, and other test procedures requiring small, homoge-neous specimens
37、.8.2 Visible Inspection Procedures:8.2.1 Inspection Table for Large, Visible Contaminants:8.2.1.1 Using a laboratory spatula, spread 450 6 20gofrecycled plastic flakes or pellets on a clean, white inspectiontable.8.2.1.2 Without the benefit of magnification, describe thetypes of individual contamina
38、nt “particles” as defined in 3.2.7,then using 103 magnification, describe the “specks” as definedin 3.2.8.8.2.1.3 Thermal techniques (see 7.5) and infrared analysis(see 7.6) can be used to identify some of the isolated contami-nants.NOTE 5To obtain a quantitative estimate of the contaminants, thesec
39、ontaminants can be removed and weighed, but there is not existingprecision and bias data related to this estimated contaminant concentra-tions in recycled plastics.8.2.2 Inspection of Molded Specimens or Plaques:8.2.2.1 Weigh 4 to5gofdryplastic flake on to a polyestersheet or aluminum foil in a 15.2
40、 by 15.2 by 0.013-cm mold.Cover with another sheet of polyester film or aluminum foil,then adjust the press temperature to at least 10C above themelting temperature of the bulk of the test material.8.2.2.2 Press a plaque from the recycled plastic sample.Remove the plaque from the press and cool.8.2.
41、2.3 Visually examine the test plaque within a 10-cm2area using a fluorescent-light table. For comparison, repeat8.3.1 and 8.3.2 with a portion of virgin resin representing thebulk of the test material (for example, poly(ethylene tereph-thalate) (PET) if you are interested in contaminants in recycled
42、PET).NOTE 6The presence of glue contamination is indicated by bondingof the plastic to the polyester sheet used as a release material duringmolding of the plaque.NOTE 7An alternative procedure for poly(ethylene terephthalate)involves melting pellets for 10 min at 275C in an aluminum pan. Thismelt is
43、 rapidly quenched in ice water to prevent crystallization and theresulting disk or plaque is visually inspected for contaminants and blackspecks by comparison with a control disk or plaque prepared from virginPET. In this case, black specks are attributed to degraded paper, adhesives,poly(vinyl chlo
44、ride), or other contaminants in the poly(ethylene tereph-thalate).8.3 Separations Based on Density:8.3.1 Water-Density Separation:8.3.1.1 Fill a clean plastic container with 2 L of clean water.Add sufficient nonionic surfactant to make a 2 % (weight/volume) solution and mix thoroughly.NOTE 8Acknowle
45、dging that water quality varies from one part of thecountry to another, minimum water quality for this test includes propertiesof Type III grade reagent water as defined in Specification D1193.NOTE 9Air pockets within flake material may cause the material tofold back on itself. The surfactant (for e
46、xample, Triton X-1005) helpseliminate this problem with plastic flakes.8.3.1.2 Obtain a representative sample of recycled plasticflakes (see 6.1) and weigh 100 6 10 g into a clean, dry plasticcontainer.NOTE 10The sample should be free of particles identified by aprocedure such as that described in 8
47、.1.8.3.1.3 Add the surfactant solution from 8.3.1.1 to thesample container and mix well with a spatula. Allow solids tosettle for at least 5 min.8.3.1.4 Skim light plastic and any contaminants (for ex-ample, paper) from the top of the water using a small kitchenstrainer. Transfer these materials to
48、a larger strainer and rinsewith water to remove residual surfactant.8.3.1.5 Pour the remaining contents from the sample con-tainer (see 8.3.1.4) through another large strainer and washthese heavier materials with water to remove residual surfac-tant.8.3.1.6 If desired, these collected heavy material
49、s are driedand characterized by thermal (see 7.5) or infrared (see 7.6)techniques.8.3.2 Propanol/Water Density Separation:8.3.2.1 Add 1840 mL of 2-propanol and 1660 mL of water(drinking, distilled, or deionized) to a 4-L plastic bottle. Mixwell to provide a solution containing 52 % (volume:volume)2-propanol in water.8.3.2.2 Pour 200 mL of the solution from 8.3.2.1 into a500-mL graduated cylinder and measure the specific gravity ofthis solution with a hydrometer. The specific gravity should bebetween 0.914 and 0.917. If not, add small amounts of2-propanol
