1、BRITISH STANDARDBS EN ISO 294-4:2003Plastics Injection moulding of test specimens of thermoplastic materials Part 4: Determination of moulding shrinkageICS 83.080.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g
2、48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Incorporating CorrigendaApril and June 2003, and November 2007 National forewordThis British Standard is the UK implementation of EN ISO 294-4:2003. It is identical with ISO 294-4:2001, incorporating corrigendum November 2007. It super
3、sedes BS EN ISO 294-4:1998 which is withdrawn.The start and finish of text introduced or altered by corrigendum is indicated in the text by tags. Text altered by ISO corrigendum November 2007 is indicated in the text by .The UK participation in its preparation was entrusted to Technical Committee PR
4、I/21, Plastics test methods.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard
5、cannot confer immunity from legal obligations.BS EN ISO 294-4:2003This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2003 BSI 2010Amendments/corrigenda issued since publicationAmd. No. Date Comments 14432 Corrigendum No. 13 April 200
6、3 Corrected EN ISO foreword page14459 Corrigendum No. 218 June 2003 National foreword corrected28 February 2010 Implementation of ISO corrigendum November 2007ISBN 978 0 580 61879 6EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 294-4February 2003ICS 83.080.20 Supersedes EN ISO 294-4:1998Engli
7、sh versionPlastics - Injection moulding of test specimens of thermoplasticmaterials - Part 4: Determination of moulding shrinkage (ISO 294-4:2001)Plastiques - Moulage par injection des prouvettes dematriaux thermoplastiques - Partie 4: Dtermination duretrait au moulage (ISO 294-4:2001)Kunststoffe -
8、Spritzgieen von Probekrpern ausThermoplasten - Teil 4: Bestimmung derVerarbeitungsschwindung (ISO 294-4:2001)This European Standard was approved by CEN on 27 December 2002.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this Europea
9、nStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre or to any CEN member.This European Standard exists in three official versions (English, French
10、, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, F
11、inland, France, Germany, Greece,Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovak Republic, Spain, Sweden, Switzerland andUnited Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue d
12、e Stassart, 36 B-1050 Brussels 2003 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 294-4:2003 ECORRECTED 2003-03-19ForewordThe text of ISO 294-4:2001 has been prepared by Technical Committee ISO/TC 61 “Plastics“ ofthe Internatio
13、nal Organization for Standardization (ISO) and has been taken over as EN ISO294-4:2003 by Technical Committee CEN/TC 249 “Plastics“, the secretariat of which is held byIBN.This European Standard shall be given the status of a national standard, either by publication ofan identical text or by endorse
14、ment, at the latest by August 2003, and conflicting nationalstandards shall be withdrawn at the latest by August 2003.This document supersedes EN ISO 294-4:1998.According to the CEN/CENELEC Internal Regulations, the national standards organizations ofthe following countries are bound to implement th
15、is European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland andthe United Kingdom.Endorsement noticeThe text of ISO 294-4:2001 has been approv
16、ed by CEN as EN ISO 294-4:2003 without anymodifications.NOTE Normative references to International Standards are listed in Annex ZA (normative).“3%.)3/%.)3/INTERNATIONALSTANDARDISO294-4Second edition2001-12-15Reference numberISO 294-4:2001(E)Plastics Injection moulding of test specimens of thermopla
17、stic materials Part 4:Determination of moulding shrinkagePlastiques Moulage par injection des prouvettes de matriaux thermoplastiques Partie 4: Dtermination du retrait au moulage“3%.)3/%.)3/ii“3%.)3/%.)3/Contents Page1 Scope . 12 Normative references . 13 Terms and definitions 24 Apparatus . 35 Proc
18、edure . 36 Expression of results 67 Precision . 78 Test report 7AnnexA Reference points for length and width measurement 8Bibliography. 9iii“3%.)3/%.)3/ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISOmember bodies). The work
19、 of preparing International Standards is normally carried out through ISO technicalcommittees. Each member body interested in a subject for which a technical committee has been established hasthe right to be represented on that committee. International organizations, governmental and non-governmenta
20、l, inliaison with ISO, also take part in the work. ISO collaborates closely with the International ElectrotechnicalCommission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.Draft Intern
21、ational Standards adopted by the technical committees are circulated to the member bodies for voting.Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this part of ISO 294
22、 may be the subject of patentrights. ISO shall not be held responsible for identifying any or all such patent rights.International Standard ISO 294-4 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9,Thermoplastic materials.This second edition cancels and replaces the first
23、edition (ISO 294-4:1997), which has been technically revised.ISO 294 consists of the following parts, under the general title Plastics Injection moulding of test specimens ofthermoplastic materials: Part 1: General principles, and moulding of multipurpose and bar test specimens Part 2: Small tensile
24、 bars Part 3: Small plates Part 4: Determination of moulding shrinkage Part 5: Preparation of standard specimens for investigating anisotropyAnnex A of this part of ISO 294 is for information only.iv“3%.)3/%.)3/IntroductionSee ISO 294-1.In the injection moulding of thermoplastics, the difference bet
25、ween the dimensions of the mould cavity and those ofthe moulded articles produced from it may vary with the design and operation of the mould. Such differences maydepend on the size of the injection-moulding machine, the shape and dimensions of mouldings including anyrestrictive action this may have
26、 on the shrinkage, the degree and direction of flow or movement of the material in themould, the sizes of the nozzle, sprue, runner and gate, the cycle on which the machine is operated, the temperatureof the melt and the mould, and the magnitude and duration of the hold pressure. Moulding and post-m
27、ouldingshrinkage are caused by crystallization, volume relaxation and orientation relaxation of the material and by thermalcontraction of both the thermoplastic material and the mould. Post-moulding shrinkage may also be influenced byhumidity uptake.The measurement of moulding and post-moulding shri
28、nkage is useful in making comparisons betweenthermoplastics and in checking uniformity of manufacture.The method is not intended as a source of data for design calculations of components. Information on the typicalbehaviour of a material can be obtained, however, by carrying out measurements at diff
29、erent melt and mouldtemperatures, injection velocities and hold pressures, as well as at different values of other injection-mouldingparameters. The information thus obtained is important in establishing the suitability of the moulding material for theproduction of moulded articles with accurate dim
30、ensions.v“3%.)3/%.)3/1Plastics Injection moulding of test specimens of thermoplastic materials Part 4:Determination of moulding shrinkage1 ScopeThis part of ISO 294 specifies a method of determining the moulding shrinkage and post-moulding shrinkage ofinjection-moulded test specimens of thermoplasti
31、c material in the directions parallel to and normal to the direction ofmelt flow.For the determination of shrinkage of thermosets see ISO 25772.Moulding shrinkage as defined in this part of ISO 294 excludes the effects of humidity uptake. This is included inpost-moulding shrinkage and thus in total
32、shrinkage. For cases when post-moulding shrinkage is caused by theuptake of humidity only, see ISO 1751.Moulding shrinkage as defined in this part of ISO 294 represents the so-called free shrinkage with unrestricteddeformation of the cooling plates in the mould during the hold period. It may be cons
33、idered therefore as the maximumvalue of any restricted shrinkage.2 Normative referencesThe following normative documents contain provisions which, through reference in this text, constitute provisions ofthis part of ISO 294. For dated references, subsequent amendments to, or revisions of, any of the
34、se publications donot apply. However, parties to agreements based on this part of ISO 294 are encouraged to investigate the possibilityof applying the most recent editions of the normative documents indicated below. For undated references, the latestedition of the normative document referred to appl
35、ies. Members of ISO and IEC maintain registers of currently validInternational Standards.ISO 294-1:1996, Plastics Injection moulding of test specimens of thermoplastic materials Part 1: Generalprinciples, and moulding of multipurpose and bar test specimensISO 294-3: 2002 , Plastics Injection mouldin
36、g of test specimens of thermoplastic materials Part 3: Smallplates“3%.)3/%.)3/Footnote deleted3 Terms and definitionsFor the purposes of this part of ISO 294, the terms and definitions given in ISO 294-1 together with the followingapply.3.1 moulding shrinkagedifference in dimensions between a dry te
37、st specimen and the mould cavity in which it was moulded, both the mouldand the test specimen being at room temperature when measuredNOTE 1 It is expressed as a percentage ( ) of the mould cavity dimension concerned.NOTE 2 The moulding shrinkage parallel to the melt flow direction is determined at t
38、he mid-point of the width of the testspecimen, and the moulding shrinkage normal to the flow direction at the mid-point of the length.3.2 post-moulding shrinkagedifference in the dimensions of a moulded test specimen before and after a post-moulding treatment, measured atroom temperatureNOTE 1 It is
39、 expressed in percent ( ).NOTE 2 The post-moulding shrinkage parallel to the melt flow direction and the post-moulding shrinkage normal to theflow direction are defined in analogous fashion to and in 3.1.3.3 total shrinkagedifference in dimensions between a test specimen after a post-moulding treatm
40、ent and the mould cavity in which itwas moulded, measured at room temperatureNOTE 1 It is expressed in percent ( ).NOTE 2 The total shrinkage parallel to the melt flow direction and the total shrinkage normal to the flow direction aredefined in analogous fashion to and in 3.1.3.4 cavity pressurepres
41、sure of the thermoplastic material in the cavity at any time during the moulding process, measured centrally nearthe gateNOTE It is expressed in megapascals ( ).3.5 cavity pressure at holdcavity pressure (3.4) after the end of the injection time (see Figure 1)NOTE It is expressed in megapascals ( ).
42、SM%SMpSMnSP%SPpSPnSMpSMnST%STpSTnSMpSMnpCMPapCH1s tIMPa2“3%.)3/%.)3/4Apparatus4.1 Type D2 ISO mould, giving plate specimens, as specified in ISO 294-3: 2002 ,subclause 4.1.Reference marks may be engraved in the mould cavity to facilitate the measurement of the dimensions of the testspecimens produce
43、d from the mould using optical techniques. Such reference marks, if used, shall be located at adistance of from the edges of the mould cavity.It is recommended that such marks be at most in depth in order to ensure that they do not restrict the shrinkageprocess in any way (see Introduction). Pins in
44、serted in the correct plane have also been used successfully.Installation of a pressure sensor P, recommended for parts 1 and 3 of this International Standard see ISO294-1:1996, 4.1.1.4, item k) and ISO 294-3: 2002 , Figure 2, is mandatory for shrinkage measurements.The mould plates used shall be ri
45、gid enough to avoid the moulded plates being thicker than the depth of the cavity,for the whole range of hold pressures that result in positive shrinkage in length or width.4.2 Injection-moulding machine, in accordance with 4.2 of ISO 294-3: , but adding the following tolerance limits to the list of
46、 operating conditions given in 4.2.2 of ISO 294-1:1996:Cavity pressure, 4.3 Measuring equipment, capable of measuring the length and width of each test specimen and of the mouldcavity to within , the measurements being made between the centres of opposite sides or between theopposite edges or betwee
47、n pairs of reference marks (see annex A). When measuring the length of a test specimen,take care to include the 0,5-mm-high step at the gate end of the specimen. If a mechanical instrument is used,ensure that the jaws of the instrument do not produce a significant indentation.It is recommended that
48、a calibration plate be used to periodically check the measuring equipment.4.4 Oven, necessary only if post-moulding shrinkage is to be measured, by agreement between the interestedparties.5 Procedure5.1 Conditioning of materialAs specified in ISO 294-1:1996, 5.1.5.2 Injection moulding5.2.1 For the basic injection-moulding conditions, see
