1、Designation: D 6288 98 (Reapproved 2003)Standard Practice forSeparation and Washing of Recycled Plastics Prior toTesting1This standard is issued under the fixed designation D 6288; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 The practice describes a procedure for separating re-cycled plastics based on their color (for example, gre
3、en versuscolorless) and a procedure for washing dirty, ground plasticwhich results in separation of light materials (density 1.00g/cm3). This practice is not intended to represent genericwashing procedures used in the plastics recycling industry. Thedescribed procedures are solely for preparation of
4、 plasticsamples for use in other analytical tests. The procedureincludes a room temperature wash step to facilitate separationof paper (for example, labels) followed by washing at anelevated temperature.NOTE 1Although not presented as a quantitative method, the proce-dure presented in this practice
5、may be used to provide quantitative results.The user assumes the responsibility to verify the reproducibility ofquantitative results.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with it
6、s 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.NOTE 2There is no equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 1600 Terminology for Abbrevi
7、ated Terms Relating toPlastics2D 5033 Guide for the Development of Standards Relating tothe Proper Use of Recycled Plastics3D 5814 Practice for Determination of Contamination inRecycled Poly(Ethylene Terephthalate) (PET) Flakes andChips Using a Plaque Test3E 5991 Practice for Separation and Identifi
8、cation of Poly-(Vinyl Chloride) (PVC) Contamination in Poly(EthyleneTerephthalate) (PET) Flake3IEEE/ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System43. Terminology3.1 The terminology used in this practice is in accordancewith Terminology D 1600 and Guide
9、 D 5033. Units andsymbols are in accordance with Standard IEEE/ASTM SI 10.3.2 Definitions of Terms Specific to This Standard:3.2.1 light materialpaper, polymers such as polyethyleneand polypropylene, and other materials with densities less than1.00 g/cm3.4. Summary4.1 Different colored (for example,
10、 green versus colorless)plastic materials are readily distinguished by visual inspectionof a sample.4.2 Labels, glue residues and other plastics may absorb thedyes used in some procedures for identifying contaminants orthese other contaminants may exhibit interfering fluorescence.Consequently, a sta
11、ndard procedure is provided for washingthe plastic prior to examination by these tests.4.3 This practice utilizes a room temperature wash step tofacilitate separation of paper (for example, labels) followed bywashing at an elevated temperature to permit separation ofplastics and other contaminants b
12、ased on densities. The roomtemperature wash step effectively removes labels withoutactivating some adhesives.NOTE 3The dye and fluorescence tests that may require plasticwashed by this procedure are specifically designed to detect poly(vinylchloride) (PVC) contamination.4.4 Washed recycled plastic m
13、aterials are then used for testssuch as those described in Practices D 5814 or D 5991.5. Significance and Use5.1 Dirt, paper and mixtures of polymeric materials com-plicate the interpretation of data from procedures used toidentify and, if desired, quantify the contaminants in recycledplastics.1This
14、 practice is under the jurisdiction of ASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.95 on Recycled Plastics.Current edition approved July 10, 2003. Published September 2003. Originallyapproved in 1998. Last previous edition approved in 1998 as D 6288 - 98.2Annua
15、l Book of ASTM Standards, Vol 08.01.3Annual Book of ASTM Standards, Vol 08.03.4Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Bright Aluminum Tray, shallow depth (750 mm), wit
16、hminimum area of 774 cm2120 in.2.6.2 Balances, suitable for weighing 500 g of flake.6.3 Baffled Beaker, stainless steel, 15.2 cm 6 in. diameterwith four 1.9 cm 0.75 in. baffles providing a slurry height/diameter ratio of 0.9.6.4 Cover for Beaker (see 6.3) which can accommodate athermometer (or other
17、 temperature sensing device) and thestirring impeller rod.6.5 Overhead Stirrer, capable of 1000 r/min.6.6 Stirring Impeller, pitched three blade, 7.62 cm 3 in.diameter.6.7 Plastic Pails, 19 L 5 gal.6.8 Strainer, non-aluminum to fit the pails described in 6.7.6.9 Hot Plate.6.10 Thermometer.6.11 Manua
18、l Stirring Rod.6.12 Oven, capable of drying plastic flakes at 60 6 2C.7. Materials7.1 Water, distilled or deionized.7.2 Sodium Hydroxide, granular.7.3 Detergent, nonionic surfactant.NOTE 4Nonylphenol or octylphenol derivatives are effective deter-gents for this procedure. Users of this procedure sho
19、uld be aware thatthese materials have been linked to endocrine/estrogen activity and falsepositive interferences with breast cancer research. Anionic detergents mayalso be effective.7.4 Wash solution, consisting of 2 L of water, 0.3 % (6 g)nonionic surfactant (see 7.3), and 1 % (20 g) sodium hydroxi
20、de(see 7.2). Dissolve the surfactant in cold water prior to additionof the sodium hydroxide.8. Procedures8.1 Separation of Plastics Based on Color:8.1.1 Spread a representative portion of the recycled plasticon an aluminum tray.NOTE 5Use an appropriate sampling technique to insure that thesample use
21、d for this test is representative of the entire gaylord or bale ofmaterial.8.1.2 Visually inspect the recycled plastic and separate thematerials based on color (for example, green versus colorless).8.2 Room Temperature Washing Procedure:NOTE 6Although not required for all plastics, the room temperat
22、urewashing procedure is useful to remove labels from some products. Thisstep can reduce filter screen plugging from paper because the lowtemperature does not activate some adhesives.8.2.1 Place the wash solution (see 7.4) in the baffled beaker(see 6.3).8.2.2 Select and accurately weigh 500 6 20 g of
23、 dirtyplastic from the sample. Add this sample to the solution in thebeaker.8.2.3 Insert the overhead stirrer so that the impeller is 2.54cm 1 in. above the bottom of the beaker.8.2.4 Turn on the overhead stirrer and adjust the speed to1000 r/min. Continue agitation for 15 min at room temperature(25
24、 6 2C).NOTE 7Bubbles may be attached to plastic flakes and these bubblesmay cause heavy materials to float when they would otherwise sink. Usinga screen to gently disturb the floating particles and cause release of the airmay permit these heavy materials to sink instead of float.8.2.5 After 15 min,
25、turn off the overhead stirrer and removeit from the baffled beaker. Wait 5 min to allow paper and otherlight materials to rise to the surface and polymers such as PETand PVC to sink. Using the manual stirring rod (see 6.11),gently agitate the light materials to allow any trapped PET orPVC to sink.8.
26、2.6 Place a strainer (see 6.8) over a 19 L pail (see 6.7).Carefully pour the wash solution from the beaker through thestrainer causing the light materials to be trapped on the strainer.Do not allow the heavier plastic material that settled in thebeaker to be transferred to the strainer.8.2.7 Add wat
27、er to the beaker to raise the water level towithin several inches of the top.8.2.8 Agitate this plastic/water mixture with the manualstirring rod to further separate any trapped light materials.Allow any heavier polymers to sink to the bottom of thebeaker, then pour the majority of the water through
28、 the strainerinto the pail.8.2.9 Rinse the light materials in the strainer for 2 min withcold water (see 7.1) while agitating the material with themanual stirring rod. Drain rinse water into the pail.8.2.10 Transfer the trapped light materials from the strainerto paper towels and allow them to air d
29、ry.NOTE 8To shorten the drying time, place the isolated light materialsin an oven at 60 6 2C.8.3 Elevated Temperature Washing Procedure:8.3.1 Place wash solution (see 7.4) into a baffled beaker (see6.3) and heat to 88 6 2C 190 6 5F on a hot plate. Coverthe beaker (see 6.4) to minimize evaporation.8.
30、3.2 Select and accurately weigh 500 6 20 g of dirtyplastic from the sample. Add this sample to the solution in thebeaker. If the room temperature wash procedure (see 8.2) wasused to separate labels and other light materials, transfer all ofthe heavy plastic from the beaker (see 8.2.8) to the beaker
31、withthe wash solution at 88 6 2C 190 6 5F. Be careful totransfer all material from the first beaker.8.3.3 Insert the overhead stirrer so that the impeller is 2.54cm 1 in. above the bottom of the beaker and return thesolution temperature to 88 6 2C 190 6 5F.8.3.4 Turn on the overhead stirrer and adju
32、st the speed to1000 r/min. Continue agitation for 15 min while maintainingthe solution temperature at 88 6 2C 190 6 5F.8.3.5 After 15 min, turn off the overhead stirrer and removeit from the baffled beaker. Remove the beaker from the hotplate.8.3.6 Place a strainer (see 6.8) over a 19 L pail (see 6.
33、7).Carefully pour the wash solution from the beaker through thestrainer causing the solid material to be trapped on the strainer.8.3.7 Add warm water (88 6 2C 190 6 5F) to thebeaker to raise the water level to within several inches of thetop. Agitate this plastic/water mixture with the manual stirri
34、ng,then pour the majority of the water through the strainer into thepail.D 6288 98 (2003)28.3.8 Rinse the material in the strainer for 2 min with coldwater (see 7.1) while agitating the material with the manualstirring rod. Drain rinse water into the pail.8.3.9 Transfer the trapped materials from th
35、e strainer to thealuminum tray (see 6.1) and oven dry at 60 6 2C.9. Keywords9.1 contamination; poly(ethylene terephthalate) (PET);poly(vinyl chloride) (PVC); recycled plastics; washingASTM International takes no position respecting the validity of any patent rights asserted in connection with any it
36、em 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 com
37、mittee 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 standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a
38、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 Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Driv
39、e, 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).D 6288 98 (2003)3
