1、Designation:D 5940 96Standard Practice forPreparing Small Plate Test Specimens of Thermoplastics byInjection Moulding1This standard is issued under the fixed designation D 5940;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 In this part of this practice,the two-cavity ISO molds,Types D1 and D2,are defined for injection molding smallplates 6
3、0 by 60 mm,with the preferred thicknesses of 1 mm(Type D1)and 2 mm(Type D2),which can be used for avariety of tests(seeAnnexA1).The molds may additionally beequipped by inserts for studying the action of weld lines(seeAnnex A2).1.2 This practice is identical to ISO 294-3.1.3 The values stated in SI
4、units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 prac
5、tices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 5935 Practice for PlasticsAcquisition and Presentationof Comparable Single-Point Data2D 5938 Guide Describing the General Principles for Deter-mination of Tensile Properties of Pl
6、astics2D 5939 Practice for Preparing Multipurpose Test Specimensand Bars of Thermoplastics by Injection Molding22.2ISO Standards:3ISO 294-3 Injection Moulding of Test Specimens of Ther-moplastic MaterialsPart 3:Plates(ISO Moulds Type D)ISO 294-1 PlasticsInjection Moulding of Test SpecimensofThermopl
7、asticsPart1:GeneralPrinciples,Multipurpose-Test Specimens(ISO Mould Type A)andBars(ISO Mould Type B)ISO 294-4 PlasticsInjection Moulding of Test Specimensof ThermoplasticsPart 4:Determination of MouldingShrinkageISO 6603-1:1985 PlasticsDetermination of MultiaxialImpact Behaviour of Rigid PlasticsPar
8、t 1:Falling DartMethodISO 6603-2:1989 PlasticsDetermination of MultiaxialImpact Behaviour of Rigid PlasticsPart 2:InstrumentedPuncture Test3.Terminology3.1 DefinitionsSee Practice D 5939,Section 3.4.5.Apparatus5.1 ISO Molds,Type D:5.1.1 Plates 60 by 60 mm shall be molded in the Type Dtwo-cavity ISO
9、molds;see Fig.1.The small plates molded byType D shall have dimensions as given in Fig.2.5.1.2 The main construction details of the Type D ISOmolds shall conform to Fig.1 and Fig.2 and to the followingrequirements:5.1.2.1 See Practice D 5939,4.1.3.1.5.1.2.2 Not relevant;5.1.2.3 See Practice D 5939,4
10、.1.3.3 and 4.1.3.5.5.1.2.4 Not relevant;5.1.2.5 See Practice D 5939,4.1.3.6.5.1.2.6 See Practice D 5939,4.1.3.7,but relating to ISO6603;the essential dimensions in mm are as follows(see Fig.2):Length of the plate,60 to 62Width of the plate,60 to 62Thickness of the plate,Type D2,2.0 to 2.1Thickness o
11、f the plate,Type D1,1.0 to 1.15.1.2.7 See Practice D 5939,4.1.3.8 through 4.1.3.10.5.1.2.8 Fig.2 shows the position of a pressure sensor,P,within the cavity,which is mandatory for the measurement ofmolding shrinkage only;see ISO 294-4.However,it may besuitable for controlling the injection period us
12、ing any ISOmold;see Practice D 5939,4.1.3.11.The pressure sensor shallbe coplanar with the mold surface in order to prevent distur-bance from flow.5.1.2.9 See Practice D 5939,4.1.3.12 through 4.1.3.15.NOTE1Gates with strongly reduced thickness have a great influenceon the orientation of the material
13、 within the plate up to large distancesfrom the gate.Therefore,the thickness step at the gate has been chosen ata minimum value to facilitate measuring the molding shrinkage mechani-cally;see ISO 294-4.1This practice is under the jurisdiction of ASTM Committee D-20 on Plasticsand is the direct respo
14、nsibility of Subcommittee D20.61 on USATechnicalAdvisoryGroup for ISO/TC 61 on Plastics.Current edition approved June 10,1996.Published August 1996.2Annual Book of ASTM Standards,Vol 08.03.3Available from American National Standards Institute,11 W.42nd St.,13thFloor,New York,NY 10036.1AMERICAN SOCIE
15、TY 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.NO
16、TE2The thickness and length of the gate strongly influence theprocess of the freezing of the melt flow into the cavity and thus themolding shrinkage;see ISO 294-4.The dimensions of the gate aretherefore defined with low tolerances.NOTE3The indicated value of the gate length,lG,allows separatingthe plates from the runner by stamping or sawing using a fixed distance,lC,between the cutting lines(see Fig.1),even for materials with differentshrinkages.NOTE4The distance,lC,between cutting lines for se