ASTM_D_5939_-_96.pdf

Designation:D 5939 96Standard Practice forPreparing Multipurpose Test Specimens and Bars ofThermoplastics by Injection Moulding1This standard is issued under the fixed designation D 5939;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice covers the general principles to be fol-lowed for injection moulding test specimens of thermoplasticsand gives details of mould designs for preparing specimentypes for reference data,that is,for multipurpose-test speci-mens according to ISO 3167(Specification D 5936)and forbars 80 mm 3 10 mm 3 4 mm.This practice provides a basisfor establishing reproducible moulding conditions.This prac-tice promotes uniformity in describing the various essentialparameters of the moulding operation and also establishes auniform practice in reporting moulding conditions.The specialconditions required to prepare test specimens in a comparableand reproducible state will vary for each material used.Theseconditions are given in the ISO standard for the relevantmaterial or are to be agreed upon between interested parties.NOTE1ISO round-robin tests with acrylonitrile/butadiene/styrene(ABS),styrene/butadiene(S/B)and polymethylmethacrylate(PMMA)showed that design of the mould is one of the important factors inpreparation of test specimens.1.2 This practice is identical to ISO 294-1.This standard iscomparable to Practice D 3641 but neither standard should besubstituted for the other.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 3641 Practice for Injection Molding Test Specimens ofThermoplastic Molding and Extrusion Materials2D 5935 Practice for PlasticsAcquisition and Presentationof Comparable Single-Point Data3D 5936 Specification for Multipurpose Test SpecimensUsed for Testing Plastics3D 5940 Practice for Preparing Small Plate Test Specimensof Thermoplastics by Injection Moulding3D 5942 Test Method for Determining Charpy ImpactStrength of Plastics32.2ISO Standards:4ISO 179:1993 PlasticsDetermination of Charpy ImpactStrengthISO 294-1 Injection Moulding of Test Specimens of Ther-moplastic MaterialsPart 1:General Principles,Multi-purpose Test Specimens and BarsISO 294-2 PlasticsInjection Moulding of Test Specimensof ThermoplasticsPart 2:Small Tensile Bars(ISOMould Type C)ISO 294-3 PlasticsInjection Moulding of Test Specimensof ThermoplasticsPart 3:Small Plates(ISO MouldsType D)ISO 294-4 PlasticsInjection Moulding of Test Specimensof ThermoplasticsPart 4:Determination of MouldingShrinkageISO 3167:1993 PlasticsMultipurpose Test SpecimensISO 10350:1993 PlasticsThe Acquisition and Presenta-tion of Comparable Single-Point DataISO 11403-1:1994 PlasticsAcquisition and Presentationof Comparable Multipoint DataPart 1:MechanicalPropertiesISO 11403-2 PlasticsAcquisition and Presentation ofComparable Multipoint DataPart 2:Thermal and Pro-cessing PropertiesISO 11403-3 PlasticsAcquisition and Presentation ofComparable Multipoint DataPart 3:Environmental In-fluences on Properties3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 cavity,nthe part of hollow space of the mould thatforms one specimen.3.1.2 clamping force FM,nthe force clamping the platesof the mould.It is expressed in kilonewton,kN.The minimumclamping force is calculated according to Eq 1.FM$AP3 Pmax3 1023(1)where:1This practice is under the jurisdiction of ASTM Committee D-20 on Plasticsand is the direct responsibility of Subcommittee D20.61 on U.S.TechnicalAdvisoryGroup for ISO/TC 61 on Plastics.Current edition approved June 10,1996.Published August 1996.2Annual Book of ASTM Standards,Vol 08.02.3Annual Book of ASTM Standards,Vol 08.03.4Available from American National Standards Institute,11 W.42nd St.,13thFloor,New York,NY 10036.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMNOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.FM5 the clamping force(see 3.1.2),in kN,AP5 the projected area(see 3.1.18),in mm2,andPmax5 the maximum value of the melt pressure(see3.1.12),in MPa.3.1.3 cooling time tC,nthe time from the end of theinjection period until the mould starts to open.It is expressedin seconds,s.3.1.4 critical cross-sectional area AC,ncross-sectionalarea of a cavity of a single-or multi-cavity mould at theposition that forms the critical portion of the test specimen.Itis expressed in sq