1、Designation:D239620Standard Test Methods forPowder-Mix Time of Poly(Vinyl Chloride)(PVC)ResinsUsing a Torque Rheometer1This standard is issued under the fixed designation D2396;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 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 These test methods cover the determination of thepowder-mix time of a general-purpose poly(vinyl chloride)(PVC)resin.1.
3、2 The values stated in SI units are to be regarded asstandard.1.3 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,health,and environmental practices and deter-mine
4、 the applicability of regulatory limitations prior to use.NOTE1ISO 4574-2019 is covering the primary subject of this ASTMmethod.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for th
5、eDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsE456 Terminol
6、ogy Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2935 Practice for Conducting Equivalence Tests for Com-paring Testing Processes3.Terminology3.1 Definitions:3.1.1 Terms used in this standard are defined in accordan
7、cewith Terminology D883,and abbreviations are in accordancewith Terminology D1600 unless otherwise specified.For termsrelating to precision and bias and associated issues,the termsused in this standard are defined in accordance with Terminol-ogy E456.4.Summary of Test Methods4.1 A sample of resin is
8、 heated and mixed in a bowl to thetest temperature.A measured amount of plasticizer is added tothe resin through a dispersing funnel.When the plasticizer isadded to the resin,the mix becomes wet and an increase inmotor torque is needed to maintain the same rotor speed.As themixing continues in the h
9、eated bowl,the plasticizer is absorbedinto the resin and the resin granules become dry and free-flowing.When the mix reaches the dry and free-flowing state,its resistance to stirring decreases and the motor torque neededto maintain the same rotor speed decreases.By recording thechanges in motor torq
10、ue with time,it is possible to measure thetime required for a resin to absorb a plasticizer.4.2 These test methods describe the use of two differentmixing heads that can be mounted on a torque rheometer toperform this test.Test results obtained with these mixing headsare compared in Section 14.4.2.1
11、 A sigma mixing head is used in Test Method A.4.2.2 A planetary mixing head is used in Test Method B.5.Significance and Use5.1 The ability of PVC granules to accept a plasticizer andbecome a dry free-flowing powder is related to the internalpore structure of the resin,resin temperature,plasticizerte
12、mperature,and the plasticizer used.By choosing an appli-cable plasticizer and maintaining a uniform temperature for theresin and plasticizer,it is possible to classify resins by howrapidly they absorb plasticizer.Resin suitability for a specificintensive mixing operation can be ascertained using the
13、se testmethods.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Dec.1,2020.Published December 2020.Originallyapproved in 1969.Last previous edition approved in 2
14、012 as D2396-94(2012).DOI:10.1520/D2396-20.2For 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.Copyright ASTM Internat
15、ional,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides an
16、d Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.16.Interferences6.1 ResinEach resin has a specific response in accepting aplasticizer.Differences in powder-mix time between resins canbe observed in the graph in the annex.6.2 PlasticizerPlasticizerviscositydirectlyaffectspowder-mix time.Table 1 shows that an increase in diisodecylphthalate(DIDP)viscosity results in an increase in powder-mix time.The data in Table 1 was generated in a singlelabora
