1、BRITISH STANDARDBS 857:1967Incorporating Amendments Nos. 1, 2, 3, 4 and 5Safety glass for land transportCONFIRMED g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43
2、g55g3g47g36g58ICS 03.220.01; 81.040.30Specification forSEPTEMBER 1990Co-operating organizationsThe BrisciBritish Glass Industry ResGlasSoUnThe orgfollopreAutomobile AssociationBritish Plastics FederationChFlMinistry of TBS 857:1967This British Standard, having been approved by the Glass Industry Sta
3、ndards Committee and endorsed by the Chairman of the Chemical Divisional Council, was published under the authority of the General Council on 30 June 1967 BSI 2007First published June 1939First revision November 1949Second revision April 1954Third revision (Parts 1 and 2) September 1964Fourth revisi
4、on June 1967The following BSI references relate to the work on this standard:Committee reference GLC/13Draft for comment 66/18256ISBN 978 0 580 59376 5ief Fire Officers Associationat Glass Manufacturers AssociationechnologyMinistry of TransportMinistry of Transport Road Research LaboratorySociety of
5、 Motor Manufacturers and Traders Ltd.An individual manufacturerAmendments issued since publicationAmd. No. Date of issue Comments1088 January 19733402 September 19803547 January 19813548 February 1981 Indicated by a sideline in the margin17226 31 July 2007 A.2 Apparatus “circular slit . . .” changed
6、 to “inner diameter 3.33 cm” to align with Figure 4.Glass Industry Standards Committee, under whose supervision this tish Standard was prepared, consists of representatives from the following entific and industrial organizations:earch Association*s Manufacturers Federationciety of Glass Technology*i
7、versity of Sheffield (Department of Glass Technology)anizations marked with an asterisk in the above list, together with the wing, were directly represented on the committee entrusted with the paration of this British Standard:BS 857:1967 BSI 2007ContentsPageCo-operating organizations Inside front c
8、overForeword iii1 General clauses, and optical requirements for windscreens 11.1 Scope 11.2 Definitions and general requirements 11.3 Optical requirements 22 Requirements specific to toughened safety glass 22.1 Properties and quality 22.2 Thickness 32.3 Marking 42.4 Sampling and acceptance 42.5 Unif
9、ormity test 42.6 Fragmentation test 52.7 Visual transmission 113 Requirements specific to laminated safety glass 113.1 Properties and quality 113.2 Thickness 113.3 Marking 113.4 Sampling and acceptance 123.5 Light stability test 123.6 Boil test 133.7 Fracture and adhesion test 133.8 Impact test for
10、high performance laminates 144 Requirements specific to toughened glass for use only in railway rolling stock 164.1 General 164.2 Flatness 164.3 Tong marks 164.4 Light transmission 164.5 Assessment of visual appearance 17Appendix A Test for optical deviation 18Appendix B Test for distortion of visio
11、n 18Appendix C Test for visual transmission 19Appendix D Apparatus required for uniformity test 19Appendix E Notes on fragmentation test 19Appendix F Apparatus for fracture and adhesion test and impact test 19Appendix G Optical characteristics of windscreens 20Figure 1A Idealized fracture pattern of
12、 small-zone windscreen (Type Z) 21Figure 1B, C and D Idealized fracture patterns of wide-zone windscreens (Types Z1 and Z2) 22Figure 2A Primary vision area for optical tests on windscreens 23Figure 2B Primary vision areas for optical tests on divided windscreens 24Figure 3 Particle count and size de
13、terminations 25Figure 4 Apparatus for optical deviation test 27Figure 5 Diagram of typical polariscope 28iBS 857:1967iiPageFigure 6 Frame for fracture and adhesion test and impact test 29Figure 7 Deviation and separation of images due to curvature 30Figure 8 Deviation and separation of images due to
14、 wedge 30Figure 9 Relationship between optical characteristics of a curved windscreen 31Table 1 Conditions of acceptance for windscreens (optical requirements) 2Table 2 Limits of thickness for heat-treated safety glass 3Table 3 Limits of thickness usual for heat-treated safety glass for the automobi
15、le industry 3Table 4 Summary of requirements for fragmentation tests for toughened safety glass 8Table 5 Conditions of acceptance for toughened safety glass 10Table 6 Limits of thickness for laminated safety glass 11Table 7 Conditions of acceptance for laminated safety glass 15 BSI 2007BS 857:1967 B
16、SI 2007ForewordThis standard makes reference to the following British Standard:BS 354, Recommendations for photometric integrators. This British Standard was first published in 1939 and revised editions were published in 1949 and 1954. A major amendment to the 1954 edition was issued in 1961 when th
17、e zoned type of toughened glass windscreen was introduced. This was followed in 1964 by a separate publication of Parts 1 and 2 covering, for the first time, optical requirements for all windscreens and also a further revision of the toughened glass specification including both uniform and non-unifo
18、rm wide-zone windscreens.Minor editorial changes are not tagged, the amendments in this issue are described in the amendment table.The representative technical committee which is responsible for this standard under the authority of the Glass Industry Standards Committee, continued its revision work
19、on the laminated glass sections of the 1954 specification and in particular modified these to include a more severe impact test for windscreens, thus ensuring that only so-called “high performance” laminates will be used for this purpose. At the same time the impact requirements for all laminated gl
20、ass have been made more stringent by increasing from 16 ft (4.9 m) to 30 ft (9.15 m) the height from which the ball is dropped in the fracture and adhesion test. A light stability test is included, in which the visual transmission of the laminate is measured both before and after exposure to ultravi
21、olet radiation.The toughened glass specification has also been reviewed in the light of technical advances made since 1964 and the following main changes are incorporated in the new edition.1) Only zoned glass is now included for windscreens as it is felt that the uniformly toughened glass, which ma
22、y obscure the drivers vision if it fractures, should no longer be used for windscreens.NOTE By amendment in January 1973, the application of the above provision regarding zoned glass was limited to windscreens for the general run of road vehicles, and it was recognized that uniformly toughened glass
23、 is acceptable for the windscreens of railway locomotives and of relatively slow-moving agricultural and industrial tractors.2) For purposes other than windscreens, provision has been made for the use of glass toughened by chemical treatment, instead of heat treatment, provided it meets the requirem
24、ents of the standard.3) The requirements for zoned windscreens have been made more stringent by defining the maximum size of individual particles after fracture and the test procedure for the non-uniform zone glass (Type Z2) has been modified so as to encourage the manufacture of windscreens which g
25、ive better visibility in the event of fracture.In keeping with the general changeover of the British industry to the metric system, dimensional requirements have been given in metric units throughout this revision, with the corresponding inch-lb units given also for information. The committee has st
26、udied the latest standards and proposals for safety glass in vehicles, prepared in the USA and on the continent of Europe, and where considered appropriate the specification requirements and test procedures of this standard have been harmonized with such overseas standards.The testing equipment and
27、procedure described in Appendix A to Appendix F are substantially unchanged from the earlier editions, except that Appendix F now covers the requirements of the more severe impact test referred to above. Data are also given in Appendix G, for information only, indicating the effect of windscreen des
28、ign features (e.g. rake angle and designed curvature) on the optical characteristics.iiiBS 857:1967ivContractual and legal considerationsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a Britis
29、h Standard cannot confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 31 and a back cover. BSI 2007This standard has been updated (see copyright date) and may have had amendments incorporated. This will be ind
30、icated in the amendment table on the inside front cover.The BSI copyright notice displayed in this document indicates when the document was last issued.BS 857:19671 General clauses, and optical requirements for windscreens1.1 ScopeThis British Standard specifies requirements and tests for flat and c
31、urved safety glass for land transport, of thicknesses from 2 mm (0.08 in) to 13 mm (0.5 in).1.2 Definitions and general requirementsFor the purposes of this British Standard the following definitions apply. Mandatory general requirements, where applicable, are also given.1.2.1 safety glass (general
32、definition)a glass which, if fractured, is less likely to cause severe cuts or serious physical injury than ordinary glass1.2.2 safety glass for windscreensa glass as defined above which in addition does not cause any appreciable distortion of objects ahead of the vehicle seen through it; and which,
33、 if fractured, permits a sufficient view ahead to enable the driver to control the vehicle whilst bringing it to rest1.2.3 toughened safety glass (also known as tempered safety glass)glass which has been converted to a safety glass by subjection to a process of pre-stressing so that, if fractured, i
34、t disintegrates into small pieces. In general, its liability to fracture under the action of external forces or changes of temperature is greatly reduced by this process. Unless otherwise specified the pre-stressing is substantially uniform over the whole area of the glasspre-stressing may be carrie
35、d out by heating and rapid cooling or by chemical treatment1.2.4 heat-treated safety glass for windscreensheat-treated safety glass having a zone of modified heat treatment in which the fragmentation, if the glass is fractured, comprises sufficient pieces of larger size than elsewhere to afford bett
36、er vision through the zone than through the remainder of the glassat least the marginal part of the glass, of a width not less than 6 cm (2.5 in) shall disintegrate upon fracture into small pieces. The dimensions and location of the zone shall be agreed between the three types of zoned windscreen ar
37、e covered by this British Standard: a) Uniform small zone, Type Z, in which the stresses in the glass are substantially even throughout a zone in front of the driver (see Figure 1A).b) Uniform wide zone, Type Z1, in which the stresses in the glass are substantially even throughout a zone extending a
38、cross the greater part of the windscreen (see Figure 1B).c) Non-uniform wide zone, Type Z2, in which the stresses in the glass vary in intensity over the zone so that, if the glass is fractured, alternate areas break into fine and coarse particles respectively.NOTE Uniformly toughened safety glass c
39、omplying with the requirements of Section 2 of this standard is permitted for the windscreens of railway locomotives and of relatively slow-moving agricultural and industrial tractors capable of a speed not exceeding 20 mile/h (32.2 km/h) on level ground.in general, the alternate areas shall be arra
40、nged in a regular pattern over the zone and the stresses in corresponding areas shall be substantially the same (see Figure 1C and Figure 1D)1.2.5 laminated safety glassa product made of two or more pieces of glass firmly united to, and alternating with, one or more pieces of reinforcing material (k
41、nown as “interlayer” or “interleaf”). Fracture does not cause the glass to separate from the interlayer to any substantial extent and in general the product does not break into large fragments1.2.6 primary vision areathat part of the windscreen through which the principal field of view is obtained (
42、see Figure 2A and Figure 2B)NOTE Figure 2A excludes from the primary vision area a band round the edge of the glass 6 cm (2.5 in) wide at top and bottom and 9 cm (3.5 in) wide at the sides. Compliance with the optical requirements in 1.3 implies the avoidance of sharp curvatures throughout the prima
43、ry vision area.1.2.7 consignmentthe whole of the safety glass delivered at any one time in connection with an order or contract BSI 2007 1vehicle maker and the manufacturer of the safety glass; even in the case of half-screens the dimensions of the zone shall be not less than 40 cm (16 in) 15 cm (6
44、in)BS 857:1967Table 1 Conditions of acceptance for windscreens (optical requirements)1.3 Optical requirements1.3.1 General. The requirements detailed in 1.3.2 to 1.3.4 are specified only for windscreens and apply only to the primary vision area of the windscreen as defined in 1.2.1 6). Since this ar
45、ea necessarily varies, with different models of land transport vehicle according to the rake angle of the windscreen, seated height, distance from the windscreen and lateral placement of the driver, the vehicle manufacturer should define for each model the “eye position” to which the primary vision
46、area is related1).1.3.2 Optical deviation. When the windscreen is tested in accordance with Appendix A:1) Using the “ring and spot” target, there shall be no displacement of the secondary image2)beyond the point of tangency of the central spot image with the inside edge of the circle; this limits th
47、e secondary image separation to a maximum of 15 minutes of arc.2) Alternatively, using the “ring” target, the primary and secondary images of the circle shall either overlap or touch; this also limits the secondary image separation to a maximum of 15 minutes of arc.3) There shall not be more than on
48、e secondary image.4) From point to point in the test area there shall be no abrupt change in the displacement of the secondary image.1.3.3 Distortion of vision. When the windscreen is tested in accordance with Appendix B:1) It shall not cause breaks in the projected lines, easily seen by the un-aide
49、d eye.2) Projected lines may be bowed relative to the lines on the screen provided that these projected lines do not overlap the lines on the screen. This is equivalent to a maximum primary deviation of 8.4 minutes of arc.1.3.4 Visual transmission. When the windscreen is tested in accordance with Appendix C the visual transmission for light emitted by Standard Illuminant A shall be not less than 75 % for the primary vision area.1.3.5 Acceptance requirements (see Table 1). If all the windscreens tested (see 2.5.2 and 3.4.3) satisfy the requi
