ASTM_D_3795_-_00a2012.pdf

Designation:D379500a(Reapproved 2012)Standard Test Method forThermal Flow,Cure,and Behavior Properties of PourableThermosetting Materials by Torque Rheometer1This standard is issued under the fixed designation D3795;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.Scope*1.1 This test method covers the apparatus,and a specific testmethod,including the evaluation of results required for thedetermination of the thermal flow and cure behavior propertiesof pourable thermosetting materials.1.2 This test method can be used:1.2.1 As a control for the development and production ofpourable thermosetting materials and to measure the differentproperties(for example,melting behavior,cure behavior,etc.)as well as the influence of various additives and fillers in anygiven formulations,and1.2.2 Verify the uniformity of different production batchesof the same formulation.1.3 The values are stated in SI units.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 precau-tions are given in Section 7.NOTE1There is no similar or equivalent ISO standard.2.Referenced Documents2.1 ASTM Standards:2D792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD1898 Practice for Sampling of Plastics(Withdrawn 1998)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 For the purpose of this test method,the followingdefinitions apply,(see Fig.1):3.1.2 flow and cure behaviorthe flow behavior is repre-sented by the recorded torque curve from the loading peak(Point t1),to the torque minimum(Point t5).The cure behavioris represented by the recorded torque curve from the torqueminimum(Point t5)to the torque maximum(Point t4).The rateof curing is represented by the slope of the torque curve.3.1.3 timethe residence time at torque t5 X,where X isa factor(preferably 1.3)is tv(s).To determine tv,draw a lineat t5 X parallel with the time axis.The intersection of this linewith the left branch of the curve is t2.The intersection of thisline with the right branch of the curve is t3:tv5 t32 t2units are secondss!(1)3.1.3.1 DiscussionDepending on the manufacturer of theequipment,the software analysis program for the designatedvalues in this test method may differ(t1,t2,etc.).3.1.3.2 DiscussionUpon agreement between interestedparties,the value of X may be changed and be listed in anyreport.3.1.4 residence time or duration of plastic life(t2 t3)theresidence time is represented by a section of the recordedtorque curve in which the molten material causes the lowesttorque,s.3.1.5 total cure time(t4 t0)time from when the materialis loaded into the mixer chamber up to complete cure,s.3.1.6 torque:3.1.6.1 initial torque(t1)the initial high torque peak oncematerial is loaded into the mixer chamber.Sometimes referredto as the loading peak,Nm(Newton-meters).3.1.6.2 minimum torque(t5)the lowest point on the torquecurve representing maximum fluxing of material,Nm.3.1.6.3 final torque or cure peak(t4)the final maximumtorque value representing the final cure of material,Nm.4.Summary of Test Method4.1 A sample of thermosetting material is charged into thetemperature controlled mixer/measuring head in which the1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Proper-ties.30.08).Current edition approved Oct.1,2012.Published October 2012.Originallyapproved in 1979.Last previous edition approved in 2006 as D3795 00a(2006).DOI:10.1520/D3795-00AR12.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary 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 States1 material is compacted,melted,cross-linked,hardened,andcrushed under constant shear.5.Significance and Use5.1 The continuous recording of torque and temperaturewhile going through these various stages can be used to predictthe behavior of the material during processing.5.2 The torque rheometer test has two important functions.First,it is a means to predict flow/viscosity and cure charac-teristics of p