1、BRITISH STANDARD BS6091-2: 1987 IEC667-2: 1982 (including Amendment No.1 February1986) Vulcanized fibre for electrical purposes Part 2: Methods of test IEC title: Specification for vulcanized fibre for electrical purposes Part2: Methods of test UDC 621.315.616.92:678.542.7BS6091-2:1987 This British
2、Standard, having been prepared under the directionof the General Electrotechnical Engineering Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 30November1987 BSI 06-1999 The following BSI references relate to the work on this standard: Committee refer
3、ence GEL/16 Drafts for comment78/31124 DC and84/21286 DC ISBN 0 580 15935 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the General Electrotechnical Engineering Standards Committee (GEL/-) to Technical Committee GEL/16 upon which the fol
4、lowing bodies were represented: Adhesive Tape Manufacturers Association British Industrial Ceramic Manufacturers Association British Paper and Board Industry Federation (PIF) British Plastics Federation British Telecommunications plc Department of Trade and Industry National Measurement Accreditatio
5、n Service ERA Technology Ltd Electrical and Electronic Insulation Association (BEAMA Ltd) Electricity Supply Industry in England and Wales Electronic Engineering Association Ministry of Defence RAPRA Technology Ltd Rotating Electrical Machines Association (BEAMA Ltd) Telecommunication Engineering an
6、d Manufacturing Association (TEMA) Transmission and Distribution Association (BEAMA Ltd) The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Royal Society of Chemistry Coopted member Amendments issued since publication Amd. No. Date of issue
7、CommentsBS6091-2:1987 BSI 06-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 General notes on tests 1 3 Dimensions 1 4 Tensile strength of flat sheets 2 5 Tensile strength of rods 2 6 Tensile strength of tubes of internal diameter up to
8、and including50mm 3 7 Flexural stress at rupture of flat sheets 3 8 Flexural stress at rupture of rods 3 9 Compressive strength of corrugated sheets 4 10 Compressive strength of rod and tube 4 11 Bursting strength of flat sheets up to and including0.8mm in thickness 4 12 Tearing resistance of flat s
9、heets up to and including0.8mm in thickness 4 13 Density 4 14 Water absorption 5 15 Electric strength of flat and corrugated sheets up to and including3mm in thickness 5 16 Electric strength of tubes up to and including100mm in internal diameter 6 17 Arc resistance 6 18 Chloride content 6 19 Sulphat
10、e content 6 20 Ash content 6 21 Flexibility of flat sheets up to and including1.5mm 6 22 Moisture content 7 23 Internal ply strength of flat sheet of thicknesses up to and including10mm 7 Figure 1 Specimen for tensile strength test on tube 8 Publications referred to Inside back coverBS6091-2:1987 ii
11、 BSI 061999 National foreword This Part of BS6091 has been prepared under the direction of the General Electrotechnical Engineering Standards Committee and is identical with IEC Publication667-2:1982 “Specification for vulcanized fibre for electrical purposes Part2 Methods of test”, published by the
12、 International Electrotechnical Commission (IEC), as amended by Amendment No.1 February1986. This Part of BS6091 together with Part1 supersedes the general and test clauses of BS216:1961, BS934:1940 and BS2768:1956 which are withdrawn. The Individual sheets of IEC Publication667-3 “Specifications fo
13、r individual materials” will be available on publication from BSI Sales Department, Linford Wood, Milton Keynes MK146LE. Terminology and conventions. The text of the international standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and cer
14、tain conventions are not identical with those used in British Standards; attention is drawn especially to the following. Where, in the introduction, the word “standard” appears, it should be read as “Part of BS6091”. Wherever page numbers are quoted, they are IEC page numbers. Cross-references Inter
15、national standard Corresponding British Standard IEC554-2:1977 BS5626 Cellulosic papers for electrical purposes Part2:1979 Methods of test (Identical) IEC641-2:1979 BS5937 Pressboard and presspaper for electrical purposes Part2:1980 Methods of test (Identical) ISO62-1980 BS2782 Methods of testing pl
16、astics Methods430A to430D:1983 Determination of water absorption at23 C. Determination of water absorption at23 C with allowance for water-soluble matter. Determination of boiling water absorption. Determination of boiling water absorption with allowance for water-soluble matter (Identical) ISO/R149
17、:1960 BS3855:1965 Method for modified Erichsen cupping test for sheet and strip metal (Technically equivalent) ISO178-1975 BS2782 Methods of testing plastics Method335A:1978 Determination of flexural properties of rigid plastics (Identical) ISO287-1985 BS3433:1986 Method for determination of moistur
18、e content of paper and board by the oven-drying method (Identical) ISO1924/1-1983 BS4415 Determination of the tensile properties of paper and board Part1:1985 Constant rate of loading method (Identical) ISO1974-1974 BS4468:1969 Method for the determination of the internal tearing resistance of paper
19、 (Technically equivalent)BS6091-2:1987 BSI 06-1999 iii The Technical Committee has reviewed the provisions of the following international standards, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this Part of BS6091. Related British Stand
20、ards are given in parentheses. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. ISO2144-19
21、83 BS3631:1984 Method for determination of ash of paper and board (Identical) ISO2758-1983 BS3137:1972 Methods for determining the bursting strength of paper and board (Technically equivalent) IEC243-1967 (BS2918:1957 Determination of electric strength of solid insulating materials at power frequenc
22、ies) IEC296-1982 (BS148:1984 Specification for unused mineral insulating oils for transformers and switchgear) ISO604-1973 (No British Standard) Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to8, an inside back cover and a back cover. This standard
23、 has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS6091-2:1987 BSI 06-1999 1 Introduction This standard is one of a series which deals with vulcanized fibre for electrical purposes. The se
24、ries will have three parts: Part 1: Definitions and general requirements; Part 2: Methods of test; Part 3: Specifications for individual materials. Whenever appropriate the methods given or quoted here are identical to those given in IEC Publication641: Specification for Pressboard and Presspaper fo
25、r Electrical Purposes. 1 Scope The standard covers vulcanized fibre sheets, flat or corrugated sheets, round rods and round tubes suitable for use as electrical insulation. Material made by combining with an adhesive several thicknesses of vulcanized fibre is not covered by this standard. 2 General
26、notes on tests Unless otherwise specified, the test specimens, after being cut, shall be conditioned in an atmosphere of23 2 C, and505% r.h., and then tested in this atmosphere. The duration of the conditioning in relation to the nominal thickness for sheet and tubes shall be: nominal thickness or w
27、all thickness (mm) time (h) For rods the time shall be240h. 3 Dimensions 3.1 Thickness of flat sheets The thickness shall be determined as in Clause2 of IEC Publication641-2: Specification for Pressboard and Presspaper for Electrical Purposes, Part2: Methods of Test. The result is the central value
28、of the eight measurements. The highest and lowest values shall be reported. 3.2 Thickness of corrugated sheets Under consideration. 3.3 Dimensions of tubes 3.3.1 Outside diameter of tubes of outside diameter up to and including300mm Using a machinists micrometer or vernier calipers capable of readin
29、g to0.02mm make three measurements60 apart around the circumference near each end and the middle of the tube. The result is the central value of the nine measurements. The highest and lowest values shall be reported (see Sub-clause3.3.3). 3.3.2 Outside diameter of tubes of outside diameter above300m
30、m Using a flat steel tape, measure the circumference to the nearest0.5mm near each end and the middle of the tube. Calculate the outside diameter remembering to subtract twice the thickness of the tape. Alternatively a tape calibrated to read the diameter directly may be used. The result is the cent
31、ral value of the three determinations. The highest and lowest values shall be reported (see Sub-clause3.3.3). 3.3.3 Variation in outside diameter of tubes From the measurements of outside diameter determined as above, report the difference between the maximum and minimum readings as the variation in
32、 outside diameter. # 0.5 0.5 to1.0 1.0to2.0 2.0to3.0 3.0 48 72 96 120 240 a a If approached from the wet side then the appropriate time values are:48,96,120,240,480 h.BS6091-2:1987 2 BSI 06-1999 3.3.4 Inside diameter of tubes of inside diameter up to and including300mm At each end of the tube using
33、any device capable of measuring the inside diameter to0.02mm, make three measurements at points60 apart around the circumference. The result is the central value of the six determinations. The highest and lowest values shall be reported. 3.3.5 Inside diameter of tubes of inside diameter above300mm C
34、alculate the inside diameter by subtracting twice the central value of the measurements of wall thickness determined as in Sub-clause3.3.6 below from the central value of the measurements of outside diameter determined as in Sub-clause3.3.2 above. 3.3.6 Wall thickness Using any device capable of mea
35、suring wall thickness to within0.02mm, measure the wall thickness at three points spaced approximately equally around the circumference of the tube. Make the determinations at or near to each end of the tube. The result is the central value of the six determinations. The highest and lowest values sh
36、all be reported. 3.4 Dimensions of rods 3.4.1 Diameter of rods Using a machinists micrometer or vernier calipers capable of reading to0.02mm, make three measurement60 apart around the circumference near each end and the middle of the rod. The result is the central value of the nine measurements. The
37、 highest and lowest values shall be reported. 4 Tensile strength of flat sheets Tensile strength shall be measured according to the method described in ISO Standard1924, the load being applied at a rate of100mm/min and continued until the test piece breaks. Deviations from ISO Standard1924: five mea
38、surements are made on the test pieces cut from one direction and five measurements on test pieces cut from the direction at right angles to this; the result in each direction is the central value of the five tests in that direction. The highest and lowest values in each direction shall be reported.
39、The test results shall be expressed in newtons per square millimetre. NOTEThe machine direction of the sheet will be that corresponding to the length direction of the test piece having the greater tensile strength. 5 Tensile strength of rods Test piece The central portion of a230mm length of the rod
40、 is machined down for a length of90mm. For rods up to20mm diameter the diameter of the central portion is reduced by1.6mm. For rods of diameter greater than20mm and up to25mm the diameter of the central portion is reduced by3mm. The radius at the transition between rod and reduced portion is6mm. Thr
41、ee test pieces are tested. Apparatus Any apparatus may be used which will measure the load applied to an accuracy of1%. Procedure Measure the diameter at the centre by taking two measurements at right angles. Insert the test piece in the jaws of the machine in axial alignment with the direction of p
42、ull. Apply the load at such a rate that the stress stipulated in Part3 is reached in approximately2min and continue until the test piece breaks.BS6091-2:1987 BSI 06-1999 3 Result The tensile strength is the central value of the three test results expressed in newtons per square millimetre. The two o
43、ther values shall be reported. 6 Tensile strength of tubes of internal diameter up to and including50mm Test pieces Three test pieces shall be tested each consisting of a tube not less than150mm long with the central portion cut away as shown in Figure 1, page8. Apparatus Any apparatus may be used w
44、hich will measure the load applied to an accuracy of1%. Procedure A steel plug of the same diameter as the internal diameter of the tube shall be inserted into each end of the tube to avoid crushing the test piece during testing. The test piece may then be held in ordinary wedge shape clamps. The lo
45、ad shall be calculated from the stress stipulated in Part3 and applied in such a way that it is reached in approximately2 min and continued until the test piece breaks. The tensile strength shall be calculated from the original cross-sectional area of the wall of the tube at the point of fracture an
46、d expressed in newtons per square millimetre. Result The result is the central value of the three determinations, in newtons per square millimetre. The two other values shall be reported. 7 Flexural stress at rupture of flat sheets Flexural stress at rupture shall be determined as specified in ISO S
47、tandard178. The test pieces shall be cut from the sheet to be tested with their major axes in the directions indicated at A and B in Figure 1 of ISO Standard178; five test pieces in each direction. If the sheet to be tested is more than20mm thick, the thickness of the test pieces shall be reduced to
48、20mm by machining both faces symmetrically. The result in each direction is the central value of the five tests in that direction. The highest and lowest values in each direction are reported. 8 Flexural stress at rupture of rods The flexural stress at rupture shall be determined as specified in ISO
49、 Standard178 and in the following. Test pieces Three test pieces shall be tested. If the diameter of a rod exceeds20mm it shall be reduced concentrically to20mm by machining. The length of the test piece shall be not less than20 times its diameter. Procedure The distance between the supports shall be15 to17 times the measured diameter and shall be measured to within0.5%. The flexural stress at rupture shall be calculated from the following formula: where: W = force at fracture in newtons L = measured distance between supports in millimetres D = di
