ASTM_D_2538_-_02_2010.pdf

Designation:D253802(Reapproved 2010)Standard Practice forFusion of Poly(Vinyl Chloride)(PVC)Compounds Using aTorque Rheometer1This standard is issued under the fixed designation D2538;the number immediately following the designation indicates the year oforiginal 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.Scope1.1 This practice covers the relative fusion characteristics ofpoly(vinyl chloride)compounds.1.2 The test procedures appear in the following order:SectionFusion Test9Thermal Stability Test10Color-Hold Stability Test11Shear Stability Test121.3 The values stated in SI units are to be regarded as thestandard.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.Specific hazardsstatements are given in Section 8.NOTE1There are no ISO standards covering the primary subjectmatter of this ASTM standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nologies D883 and D1600 unless otherwise indicated.4.Summary of Practice4.1 A sample of powder-mix compound is added to theheated roller mixer chamber and is transformed into a fusedmass.4.2 The resulting torque curve can be used to determine therelative fusion time and fusion characteristics.5.Significance and Use5.1 When PVC compounds are mixed under appropriateconditions of heat and shear,a fused mass is produced.Thismass has certain melt characteristics which can be defined witha torque rheometer operated under fixed conditions of shearand temperature.The fusion characteristics of a PVC com-pound are manifest as fusion time,fusion torque,melt torque,melt viscosity,and heat and color stability.5.2 A control lot is to be used as a standard against whichother test results are to be compared.Test data are to beevaluated relative to the control lot.6.Apparatus6.1 Microprocessor Torque Rheometer,3equipped with ahigh-shear mixer with roller-style blades,bowl-jacketthermocouple,stock thermocouple,and temperature recorder.NOTE2A torque rheometer without microprocessor capability can beused to perform the fusion,thermal stability,and color hold tests.6.1.1 For flexible and rigid compounds,use a Type 6 rollerhead with a rotor ratio of 3 Drive:2 Driven.NOTE3A Type 5 roller head can also be used,but the data generatedcannot be compared with the Type 6 data.6.2 Quick-Loading Powder Chute or equivalent.6.3 Brass Knife.6.4 Brass Wool or Brush.6.5 Insulated Gloves.6.6 Balance,500-g minimum capacity,with a 0.1-g sensi-tivity.1This practice is under the jurisdiction ofASTM Committee D20 on Plastics andis the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials.Current edition approved Nov.1,2010.Published March 2011.Originallyapproved in 1969.Last previous edition approved in 2002 as D2538 02.DOI:10.1520/D2538-02R10.2For 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 ASTM website.3Suitable equipment may be obtained from C.W.Brabender,50 E.Wesley St.,South Hackensack,NJ 07606,and Haake Buchler Instruments,244 Saddle RiverRd.,Saddle Brook,NJ 07662.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.7 Beaker,stainless steel,400 mL.6.8 Oven.6.9 Aluminum Foil.6.10 Timer.6.11 Long-Nose Pliers.6.12 Hand-Press Mold.7.Materials7.1 Poly(Vinyl Chloride)Resin.7.2 Filter.7.3 Lubricants.7.4 Plasticizer.7.5 Process-Aid.7.6 Impact Modifier.7.7 Stabilizer.7.8 Pigments.8.Hazards8.1 Do not exceed the power capacity of the instrument,asdamage to the mixer or to the torque rheometer may result.8.2 Do not attempt to clean or poke objects into the mixerwhile it is running.8.3 Gloves with sufficient insulation to enable the operatorto handle the hot equipment should be worn when conductingthese tests.9.Fusion Test Method9.1 Compound Preparation:9.1.1 The compound may be beaker-mixed,blended in anintensive mixer or a ribbon blender,or blended and pelletized.If the compound is beaker-mixed,the total weight of thecompound should equal the amount charged to the roller-headbowl.9.2 Equipment Preparation:9.2.1 Mount the roller head on the torque rheometer.9.2.2 Select a temperature/rotor speed combination that willpermit the test to be completed within a reasonable timeconstraint.Suggested combinations for several types o