BS EN ISO 2818-1996 Plastics - Preparation of test specimens by machining《塑料 试样的机加工制备》.pdf

1、BRITISH STANDARD BS EN ISO Incorporating corrigendum November 2007 Plastics Preparation of test specimens by machining IMPORTANT NOTICE: Before reading this method it is essential to read BS 2782-0 Introduction issued separately ICS 83.080.01 2818:1996This British Standard, published under the autho

2、rity of the Standards Board and comes into effect on 15 July 1996 BSI 2009 First published December 1977 Second edition July 1996 ISBN 978 0 580 61132 2 National foreword This British Standard is the UK implementation of EN ISO 2818:1996. It is identical with ISO 2818:1994, incorporating corrigendum

3、 November 2007. It supersedes BS 2782-9:Method 930A:1977 which is withdrawn.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 ent

4、rusted to Technical Committee PRI/21, Testing of plastics. The Technical Committee has reviewed the provisions of ISO 3002-1:1982, ISO 3017:1981 and ISO 6168:1980 to which normative reference is made in the text and has decided that they are acceptable for use in conjunction with this standard. A li

5、st 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 cannot confer immunity from le

6、gal obligations. Amendments/corrigenda issued since publication Amd. No. Date Comments 9487 June 1997 Renumbers BS 2782-9:Method 930A:1996 as Implementation of ISO corrigendum BS EN ISO 2818:1996was BS EN ISO 2818:199 November 2007, and alignment of BSI and CEN publication dates 28 February 2009 7 B

7、SI 2008 i Contents Page Inside front cover National foreword Foreword 2 Introduction 3 1 Scope 3 2 Normative references 3 3 Definitions 3 4 Test specimens 5 5 Machinery and tools 6 6 Procedure 6 7 Test report 7 Annex A (informative) Bibliography 13 Figure 1 Geometry of the active part of cutting too

8、ls 10 Figure 2 Shape of milling chips 11 Figure 3 Chip thickness d sin the range between0,003mm and0,07mmversus rotational speed n and feed speed v fof a milling machine(R = 40mm) 11 Figure 4 Example of a circular cutter (half-section of a diamond-edged cutter) 12 Table 1 Recommended machining condi

9、tions for four types of test specimenand for notches 9 BSENISO2818:1996 blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2818 December 1996 ICS 83.080 Descriptors: Plastics, test specimens, specimen preparation, machining English version Plastics Preparation of test specimens by machini

10、ng (ISO 2818:1994) Plastiques Prparation des prouvettes par usinage (ISO2818:1994) Kunststoffe Herstellung von Probekrpern durch mechanische Bearbeitung (ISO2818:1994) This European Standard was approved by CEN on 1996-11-25. CEN members are bound to comply with the CEN/CENELEC Internal Regulations

11、which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European

12、Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national

13、standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung

14、 Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 Copyright reserved to CEN members Ref. No. EN ISO 2818:1996 E BSI 2008 2 Foreword The text of the International Standard from ISO/TC61, Plastics, of the International Organization for Standardization (ISO) has been taken over as a Europe

15、an Standard by Technical Committee CEN/TC249, Plastics, the secretariat of which is held by IBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June1997, and conflicting national standards shall

16、be withdrawn at the latest by June 1997. According to CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Net

17、herlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. BSENISO2818:1996 BSI 2008 3 Introduction The preparation of test specimens by machining influences the finished surfaces and, in some cases, even the internal structure of the specimens. Since test results are strongly de

18、pendent on both of these parameters, exact definitions of tools and machining conditions are required for reproducible test results with machined specimens. 1 Scope This International Standard establishes the general principles and procedures to be followed when machining and notching test specimens

19、 from compression-moulded and injection-moulded plastics, extruded sheets, plates and partially finished or wholly finished products. In order to establish a basis for reproducible machining and notching conditions, the following general standardized conditions should be applied. It is assumed, howe

20、ver, that the exact procedures to be used will be selected or specified by the relevant material specification or by the standards on the particular test methods. If sufficiently detailed procedures are not thus specified, it is essential that the interested parties agree on the conditions to be use

21、d. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on t

22、his International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 3002-1:1982, Basic quantities in cutting and grinding Part 1: Geom

23、etry of the active part of cutting tools General terms, reference systems, tool and working angles, chip breakers. ISO 3855:1977, Milling cutters Nomenclature. ISO 6104:1979, Abrasive products Diamond or cubic boron nitride grinding wheels and saws General survey, designation and multilingual nomenc

24、lature. ISO 6106:1979, Abrasive products Grain sizes of diamond or cubic boron nitride. 3 Definitions For the purposes of this International Standard, the following definitions apply: 3.1 Milling In this machining operation, the tool has a circular primary motion and the workpiece a suitable feed mo

25、tion. The axis of rotation of the primary motion retains its position with respect to the tool, independently of the feed motion (seeISO3855). Complete dumb-bell and rectangular test specimens, as well as notches in finished specimens, may be prepared by milling. 3.1.1 Geometry (see 3002-1 and Figur

26、e 1) Only a few details of the exact geometrical conditions of the milling tool and its position with respect to the workpiece given in ISO 3002-1 are relevant to this standard, as follows: 3.1.1.1 tool-cutting-edge angle, r the angle between the tool-cutting-edge plane P sand the assumed working pl

27、ane P f , measured in the tool back plane P r 3.1.1.2 tool back clearance, p the angle between the flank A !of the cutter and the tool-cutting-edge plane P s , measured in the tool back plane P p 3.1.1.3 tool side clearance, f the angle between the flank A !of the cutter and the tool-cutting-edge pl

28、ane P s , measured in the assumed working plane P f 3.1.1.4 tool radius, R the distance between the axis of the circular primary motion of the tool and its cutting edge 3.1.1.5 number of cutting teeth, z the number of cutting edges on the outer periphery of the rotating milling tool 3.1.2 Tool and w

29、orkpiece motions (see ISO 3002-1 and Figure 2) 3.1.2.1 rotational speed of tool, n the speed, in revolutions per minute, of the circular primary motion of the tool ISO 21950:2001, Coated abrasives Plain discs. Text deleted BSENISO2818:1996 Text deleted 4 BSI 2008 3.1.2.2 cutting speed, v c the insta

30、ntaneous velocity, in metres per minute, of the primary motion of a selected point on the cutting edge relative to the workpiece. The relationship between v cand n is given by the equation v c= n2;R 3.1.2.3 feed speed, v f the instantaneous velocity, in metres per minute, of the feed motion of a sel

31、ected point on the cutting edge relative to the workpiece 3.1.2.4 feed path, the distance, in millimetres, at any given point on the surface of the workpiece covered during the time between two successive cutting operations. The feed path is given by the equation = v f /zn 3.1.2.5 cutting depth, a t

32、he (mean) distance, in millimetres, between the surfaces of the workpiece before and after one complete milling run 3.2 Cutting of rectangular test specimens In this machining operation, rectangular test specimens are cut by means of a circular or band saw, made from hardened steel or coated with di

33、amond or cubic boron nitride powder, or cut with the aid of an abrasive disc of which the cutting edge may be coated with diamond or boron nitride powder. For further details on abrasive discs and abrasive products, see and ISO 6104. 3.2.1 Geometry 3.2.1.1 tool radius, R the distance, in millimetres

34、, between the rotary axis of a circular saw or an abrasive disc and the cutting edges of the tool 3.2.1.2 number of cutting teeth, z the number of cutting teeth on the periphery of a circular saw 3.2.2 Tool and workpiece motions 3.2.2.1 rotational speed of tool, n the speed of rotation, in revolutio

35、ns per minute, of a circular saw or an abrasive disc 3.2.2.2 cutting speed, v c the instantaneous velocity, in metres per minute, of the cutting tip of a saw tooth, or of a selected point on the cutting edge of an abrasive disc, relative to the workpiece. For a circular saw or an abrasive disc, the

36、relationship between v cand n is given by the equation v c= n2;R 3.2.2.3 feed speed, v f the instantaneous velocity, in metres per minute, of the tool feed parallel to the saw or disc plane and perpendicular to the cutting direction relative to the workpiece 3.3 Cutting of disc-shaped test specimens

37、 (seeFigure 4) In this machining operation, disc-shaped test specimens are cut from sheet material with the aid of a circular cutter with a saw-toothed edge of hardened steel or which may be coated with diamond or cubic boron nitride powder. The test specimens may also be cut by means of a milling c

38、utter with one or more teeth, as described in3.1, which moves in a circular orbit. Furthermore, the test specimens may also be cut from a roughly preshaped pack of individual sheets with the aid of a turning lathe. 3.3.1 Geometry 3.3.1.1 tool radius, R the distance, in millimetres, between the rotar

39、y axis of the circular cutter and the inner limit of the cutting edge. The tool radius is equal to the radius of the finished test specimen 3.3.1.2 number of cutting teeth, z the number of teeth on the sawtooth cutting edge of a circular cutter. If a lathe is used for cutting circular test specimens

40、, the geometrical definitions of the cutting tool are the same as those given in3.1 3.3.2 Tool and workpiece motions 3.3.2.1 rotational speed of tool, n the speed of rotation, in revolutions per minute, of a circular cutter 3.3.2.2 cutting speed, v c the instantaneous velocity, in metres per minute,

41、 of a selected point on the cutting edge relative to the workpiece. The relationship between v cand n is given by the equation v c= n2;R ISO 21950 BSENISO2818:1996 BSI 2008 5 3.3.2.3 feed speed, v f the instantaneous velocity, in metres per minute, of the tool feed parallel to the rotary axis of the

42、 circular cutter and perpendicular to the cutting direction relative to the workpiece 3.4 Planing of rectangular bars and planing or broaching of notches in finished test specimens In this machining operation, sawed or sliced rectangular bars are finished by planing. Also, notches in finished specim

43、ens can be cut by planing or broaching. 3.4.1 Geometry 3.4.1.1 tool-cutting-edge angle, r as defined in3.1.1.1 3.4.1.2 tool back clearance, p as defined in3.1.1.2 3.4.1.3 tool side clearance, f as defined in3.1.1.3 3.4.2 Tool and workpiece motions 3.4.2.1 cutting speed, v c the instantaneous velocit

44、y, in metres per minute, of the primary motion of a selected point on the cutting edge relative to the workpiece 3.4.2.2 cutting depth, a the (mean) distance, in millimetres, between the surfaces of the workpiece before and after one planing run 3.5 Stamping of arbitrarily shaped test specimens fabr

45、icated from thin sheets In this operation, arbitrarily shaped test specimens are stamped under high pressure from thin sheets by means of a tool with a sharp edge made from hardened steel and located in a plane parallel to the plane of the sheet. 3.5.1 Geometry 3.5.1.1 shape of the stamping tool the

46、 geometric shape of the stamping edge in a plane parallel to the sheet plane. The shape of the stamping tool depends on the shape of the test specimen to be stamped, along with its required dimensions and tolerances 3.5.2 Forces on the tool and tool motion 3.5.2.1 contact force, F c the force, in ne

47、wtons, applied to the stamping tool in the direction perpendicular to the sheet plane 3.5.2.2 feed speed, v f the instantaneous velocity, in metres per minute, of the feed motion of the edge plane of the stamping tool in a direction perpendicular to the sheet plane 4 Test specimens 4.1 Shape and sta

48、te of the test specimens The following types of test specimen can be prepared by the machining processes described in this International Standard: rectangular bars; notched rectangular bars; rectangular plates; curvilinear test specimens (e.g.dumb-bells); discs. The exact shape, dimensions and toler

49、ances of the test specimens shall conform to the standard for the particular test method in question. The machined surfaces and edges of the finished specimens shall be free of visible flaws, scratches or other imperfections when viewed with a low-power magnifying glass (approximately 5 magnification). Rectangular bars shall be free of twist and shall have perpendicular pairs of parallel surfaces. The surfaces and edges shall be