1、BRITISH STANDARD AEROSPACE SERIES BS2F66:1982 (Superseding BSF66) Specification for Rubber bonded cork sheets UDC 629.7.03:674.833-41BS2F66:1982 This BritishStandard, having been prepared under the directionof the Aerospace Standards Committee, was published under the authority ofthe Board of BSI an
2、d comesintoeffect on 31March1982 BSI02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/25 Draft for comment 81/71127 DC ISBN 0 580 12690 0 Foreword This BritishStandard, one of a number for rubber bonded materials, of a quality suitable for aircraft app
3、lications, was first published in1965 as a replacement for the then Ministry of Aviation Specification DTD762. This revision introduces metric (SI) units and deletes all reference to the material having inherent resistance to deleterious attack by mould growth under tropical storage conditions. Addi
4、tionally, chemical tests have been included to improve the control over the corrosive properties of the material. The Approving Authority referred to throughout this standard shall be either, a) for UK civil aviation products, the Civil Aviation Authority (or their accredited representative); or b)
5、for UK military products, the Quality Assurance Directorate nominated in the relevant Ministry of Defence contract. 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 B
6、ritish Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to5 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will
7、 be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS2F66:1982 BSI 02-2000 i Contents Page Foreword Inside front cover 1 Scope 1 2 References 1 3 Composition 1 4 Surface finish 1 5 Thickness 1 6 Physical properties 1 7 S
8、ampling 1 8 Routine inspection: testing 1 9 Packaging and marking 2 10 Inspection 2 11 Description for ordering 2 Appendix A Instrument for the measurement of thickness 3 Appendix B Method of test for flexibility 3 Appendix C Method for the determination of compressibility 3 Appendix D Method for th
9、e determination of compression set and sideflow 3 Appendix E Method for the determination of resistance to liquids 4 Figure 1 Apparatus for determining compression set and sideflow 5 Table 1 Thickness tolerance 1 Table 2 Physical properties 2 Table 3 Resistance to liquids 4ii blankBS2F66:1982 BSI 02
10、-2000 1 1 Scope This BritishStandard specifies the requirements for synthetic rubber bonded cork sheet jointing material from which gaskets can be cut or stamped. The material is suitable for use in systems involving contact with mineral oils, ester-based and other lubricating oils, petroleum fuels
11、and aqueous coolants, but it should not be used where working temperatures exceed150 C. Materials complying with all the requirements of this standard are not necessarily resistant to attack by mould growth under tropical storage conditions. The material has a high cork content in relation to synthe
12、tic rubber to give minimum sideflow (lateral spread) when compressed. 2 References This standard makes reference to the following standard publications. BS871, Abrasive papers and cloths for general purposes. BS903, Methods of testing vulcanized rubber Part A16: The resistance of vulcanized rubber t
13、o liquids Part B19: Preparation and examination of water extract. BS3150, Corrosion-inhibited ethanediol antifreeze for water-cooled engines, Type A Triethanolammonium orthophosphate and sodium mercaptobenzothiazole inhibited. BS3978, Water for laboratory use. 3 Composition 3.1 Finished material. Th
14、e finished material shall consist entirely of cork granules compounded with a binder vulcanized by heat and pressure. It shall be substantially free from water soluble matter. 3.2 Cork granules. The cork granules shall be produced from a clean, soft grade of cork and shall be substantially free from
15、 hard back, dust or other foreign matter. Reground or reclaimed cork shall not be included. 3.3 Binder. The binding agent shall be an oil-resisting rubber composition such that the finished material shall comply with the requirements of clause6. NOTEA suitable material can be compounded from a butad
16、iene/acrylonitrile copolymer. 4 Surface finish The finished material shall be uniform in texture and colour and free from visible defects. Each surface shall have a substantially smooth cut or very shallow knurled or cloth marked finish. 5 Thickness 5.1 The finished material shall be supplied in she
17、ets of the nominal thickness specified in the contract or order. NOTEThe preferred thicknesses are1mm,2mm,3mm, 5mm and7mm. 5.2 The thickness of the sheets at any point, when measured with an instrument complying with the requirements of Appendix A, shall be within the tolerances given in Table 1. Ta
18、ble 1 Thickness tolerance 6 Physical properties The finished material shall comply with the requirements shown in Table 2 and shall be tack free and without visible signs of deterioration after immersion in liquids as described in Appendix E. 7 Sampling Unless otherwise agreed with the Approving Aut
19、hority, a batch of sheet material shall consist of those sheets of the same thickness which have been prepared from one batch of the composition and vulcanized under the same conditions. One sheet shall be selected at random from each batch of sheet material and a sample piece, approximately300mm sq
20、uare, shall be cut from it for test purposes. 8 Routine inspection: testing 8.1 Unless otherwise agreed with the Approving Authority, the testing shall be as directed in8.2 to8.4. 8.2 Each sheet shall comply with the requirements of clauses4 and5. 8.3 Initially each sample piece, selected as describ
21、ed in clause7, shall be tested for compliance with all the requirements of clause6 and Table 2. 8.4 Provided that the Approving Authority is satisfied that no significant change is made in the composition, the routine inspection required for compliance with the requirements given in Table 2d) and Ta
22、ble 2e) only may be reduced as agreed with the Approving Authority. Nominal thickness Tolerance at any point mm Up to and including1 Over1 up to and including3 Over3 % 15 10 7BS2F66:1982 2 BSI 02-2000 9 Packaging and marking 9.1 The material shall be packaged in sound, clean and dry containers which
23、, after packing, shall hold an agreed quantity and shall be securely closed. 9.2 In addition to any markings on sheets and packages called for in the contract or order and by statutory requirements, each package shall be legibly and durably marked with the following details. a) Description (i.e.rubb
24、er bonded cork sheet). b) BritishStandard number, i.e.BS2F66. 1) c) Contract or order number. d) Batch number. e) Quantity of contents. f) Date of manufacture (month and year). g) Contractors name, initials or recognized trade mark. 10 Inspection If required, samples of the material shall be taken f
25、rom any portion of the consignment. If on examination any sample be found not to comply with the requirements of this standard, the whole of the relevant batch in that consignment shall be rejected. 11 Description for ordering The sheets shall be described for ordering purposes by the number of this
26、 BritishStandard together with the thickness required, i.e.3mm thick sheets shall be identified as “BS2F66/3mm”. Table 2 Physical properties 1) Marking BS2F66 on or in relation to a product is a claim by the manufacturer that the product has been manufactured in accordance with the requirements of t
27、he standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, BritishStandards Institution, Maylands Avenue, Hemel Hempstead, Herts HP24SQ in th
28、e case of certification marks administered by BSI or to the appropriate authority for other certification marks. Property Requirement Method of test a) Flexibility in any direction b) Compressibility:% No signs of cracking 25 5 Appendix B Appendix C c) Compression set:%, maximum d) Side flow:%, maxi
29、mum 35 10 Appendix D e) Resistance to liquids:% (see Table 3) 1) Change in length and width 2) Change in thickness f) Freedom from corrosion impurities 1) pH of water extract 2) Chlorides, as chloride ion in% 3) Sulphates, as sulphate ion in% 6 +12,5 5.0 to8.5 0.1max. 0.2max. Appendix E BS903-B19 BS
30、2F66:1982 BSI 02-2000 3 Appendix A Instrument for the measurement of thickness The instrument for measuring thickness shall be a gauge having a scale graduated in unit divisions of0.01mm, with a flat circular foot exerting a dead weight pressure of20 3kPa. Appendix B Method of test for flexibility B
31、.1 Test pieces Three strips each approximately100mm 10mm and of thickness that of the sheet from which they are cut. B.2 Procedure B.2.1 Condition the test pieces at65 2% relative humidity and23 2 C for at least18h immediately before the test. B.2.2 Bend each test piece through180 round a cylindrica
32、l mandrel having a diameter equal to four times the nominal thickness of the material, taking approximately2s to complete the bending. Maintain the test piece in the bent position for10s and then examine it in the bent position. Repeat the test by bending the same test piece in the reverse direction
33、 coincidental with the original bend. Appendix C Method for the determination of compressibility C.1 Test piece A disc50 0.2mm in diameter and of thickness that of the sheet from which it is cut or, for material of nominal thickness less than5mm, two or more discs of that diameter accurately superim
34、posed to give a composite test piece approximately6mm, but in no case less than5mm, thick. C.2 Procedure C.2.1 Condition the test pieces at65 2% relative humidity and23 2 C for at least18h immediately before the test. C.2.2 Place a test piece between smooth, rigid, parallel plattens at least55mm squ
35、are. C.2.3 Apply an initial pressure of203kPa and accurately measure the initial thickness (t 1 ) of the test piece. C.2.4 Increase the pressure of2.0 0.05MPa and, after1min, measure the thickness (t 2 ) of the test piece. C.3 Calculation of results Calculate the compression strain as follows. Appen
36、dix D Method for the determination of compression set and sideflow D.1 Test piece A disc13 0.5mm in diameter and of thickness that of the sheet from which it is cut or6mm, whichever is the less, or, for material of nominal thickness less than5mm, two or more discs of that diameter accurately superim
37、posed to give a composite test piece approximately6mm, but in no case less than5mm, thick. D.2 Apparatus Two or more parallel, smooth, flat steel plates, between the faces of which the test pieces are compressed, sufficiently rigid to withstand the stress without bending, sufficiently large to ensur
38、e that all the compressed test pieces are within the area of the plates, and held together by a bolt or bolts of suitable size, provided with steel spacers in the form of rings, of thickness (t s ) equal to70% of the thickness of the test piece. A suitable apparatus is shown in Figure 1. D.3 Procedu
39、re D.3.1 Condition the samples from which the test pieces are to be cut at65 2% relative humidity and23 2 C for at least18h immediately before the test. D.3.2 Cut the test pieces and keep them at the same temperature until completion of the test. D.3.3 Measure a) by means of the instrument described
40、 in Appendix A, the thickness of each test piece at three points and calculate the mean thickness (t o ) of each; b) by means of a suitable caliper gauge, the diameter of each test piece in at least two directions approximately at right angles and calculate the mean diameter (d 1 ). D.3.4 Place thre
41、e test pieces symmetrically between each pair of plates, with sheets of fine-grain glass-paper (grade0, BS871) between the plates and the test pieces, with the abrasive surfaces against the latter, allowing sufficient clearance from the spacers for the bulging of the test pieces when compressed. Com
42、pression strain% , t 1 t 2 t 1 -100 =BS2F66:1982 4 BSI 02-2000 D.3.5 Tighten the bolt or bolts so that that plates are drawn together uniformly until they are in contact with the spacers and measure the increased diameter (d 2 ) of each test piece as inD.3.3 b). D.3.6 After24h, loosen the bolt or bo
43、lts, remove the test pieces, allow a recovery period of60min and then measure the thickness (t r ) of each test piece at the thinnest point as inD.3.3 a). D.4 Calculation of results Calculate the compression set and sideflow (bulging of the test piece) as follows. a) Compression set,%= b) Sideflow,%
44、= Appendix E Method for the determination of resistance to liquids E.1 Test pieces Four pairs of strips, one of each pair with the length along the sheet and the other with the length at right angles to it, each80mm long by25mm wide and of thickness not greater than3mm (reduced to that thickness by
45、cutting or buffing where necessary). E.2 Procedure E.2.1 Accurately measure the length and width along the centre datum lines and the thickness (seeAppendix A) at two marked points on the centre datum line and approximately13mm from each end. E.2.2 Place one pair of test pieces, under the conditions
46、 given, in each of the liquids given in Table 3. Use fresh liquid for each individual test. E.2.3 Ensure that the test pieces are completely immersed in the liquid during the immersion period. E.2.4 After the specified time, remove the test pieces from the liquid and again measure the length, width
47、and thickness of each test piece (within1min of removal in the case of fuel). E.2.5 Examine the test pieces for tackiness and signs of deterioration. E.3 Calculation of results Calculate the percentage changes in the dimensions of each test piece and take the mean values for each pair of test pieces
48、 as the results. Table 3 Resistance to liquids t o t r t o t s -100 d 2 d 1 d 1 -100 Liquid Test conditions Type Specification Temperature Time a) Liquid B BS903-A16 23 2 C 48h b) Standard oil No.1 BS903-A16 120 1 C 168h c) Aqueous ethandiol Ethandiol to BS3150 Distilled water to BS3978: 2 volumes 1
49、 volume 100 1 C 168h d) Liquid101 BS 903-A16 120 1 C 48h e) Distilled water BS3978 100 C 5hBS2F66:1982 BSI 02-2000 5 Figure 1 Apparatus for determining compression set and sideflowBS 2F66:1982 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Char
