1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Specification for thermally toughened glass panels for use in domestic appliancesBS 3193:2008BS 3193:2008 BritiSh
2、 StandardPublishing and copyright informationthe BSi copyright notice displayed in this document indicates when the document was last issued. BSi 2008iSBn 978 0 580 60356 3iCS 81.040.30the following BSi references relate to the work on this standard: Committee reference CW/33 draft for comment 07/30
3、171352 dCPublication historyFirst published January 1960 Second edition december 1967 third edition September 1989 Fourth edition april 1993 Fifth edition november 2008Amendments issued since publicationAmd. No. Date Text affected BritiSh Standard BSI 2008 iBS 3193:2008ContentsForeword iiintroductio
4、n 11 Scope 12 terms and definitions 13 Performance requirements 24 Marking 2Annexesannex a (normative) Fragmentation test method 3annex B (normative) thermal shock test 4annex C (normative) impact test 5annex d (informative) Guidance for manufacturers of domestic appliances on the use of glass panel
5、s 7annex E (informative) Guidance on handling glass 9List of figuresFigure C.1 Support for glass panels in the impact test 6Figure d.1 Sudden major changes in shape 8Summary of pagesthis document comprises a front cover, an inside front cover, pages i to ii, pages 1 to 10, an inside back cover and a
6、 back cover.BS 3193:2008ii BSI 2008BritiSh StandardForewordPublishing informationthis British Standard is published by BSi and came into effect on 30 november 2008. it was prepared by technical Committee CW/33, Glass doors and panels for domestic appliances. a list of organizations represented on th
7、is committee can be obtained on request to its secretary.Supercessionthis British Standard supersedes BS 3193:1993, which is withdrawn.Information about this documentthis edition of BS 3193 reflects the experience that the fragmentation test in annex a can only be performed on panels at least 76 mm
8、76 mm in area. it also incorporates a more realistic impact test in which the impactor is a loaded vessel as opposed to a steel ball.WARNING. this British Standard calls for the use of substances and/or procedures that may be injurious to health if adequate precautions are not taken. it refers only
9、to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage.Presentational conventionsthe provisions of this standard are presented in roman (i.e. upright) type. its requirements are expressed in sentences in which the principal auxiliary
10、verb is “shall”.Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element.Contractual and legal considerationsthis publication does not purport to include all the necessary provisions of a contract. Users are responsible
11、 for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.BritiSh Standard BSI 2008 1BS 3193:2008Introductionthe purpose of this standard is to provide manufacturers and users with an assurance that glass panels fitted in domestic appliances will p
12、rovide a reasonable level of safe performance.Glass is thermally toughened to increase the thermal and mechanical strength. in the event of breakage thermally toughened safety glass fractures into numerous small fragments, the edges of which are generally blunt.Particular attention needs to be paid
13、to the design of the surrounds and fittings for glass panels. the method used to fit glass panels into domestic appliances can adversely affect their performance.this standard does not cover the abrasion or chemical resistance of glass panels. the performance of glass can deteriorate if it is subjec
14、ted to excessive or careless treatment with harsh abrasive cleaning materials.1 Scopethis British Standard specifies requirements for thermally toughened glass panels for use in domestic appliances where such panels can be exposed to thermal and/or physical shock.Methods of test for fragmentation an
15、d for resistance to thermal shock and impact are given in annexes a, B and C respectively. recommendations for manufacturers of domestic appliances on the use of glass panels are given in annex d. Guidance on handling glass is given in annex E.this British Standard does not specify performance requi
16、rements for glass panels in respect of abrasion or chemical resistance.2 Terms and definitionsFor the purposes of this British Standard the following terms and definitions apply.2.1 thermally toughened glass glass, the surface of which has been rapidly cooled from near the softening point so that a
17、residual compressive stress remains in the surface after complete cooling NOTE Also known as “tempered” or “heat-treated” glass.2.2 glass panelpanel of glass, with no sharp edges or sharp corners, that is made from toughened glass and is ready for installation, having undergone all finishing process
18、es2.3 asymmetric glass panelglass panel processed in such a way, e.g. by printing on one side, that its two surfaces give significantly different test results when subjected to the specified testsBS 3193:20082 BSI 2008BritiSh Standard3 Performance requirements3.1 GeneralWhen subjected to visual exam
19、ination, glass panels (including edges and corners) shall be free from defects (e.g. chips, cracks, scratches, blisters or inclusions) of a magnitude that could impair performance in use or such that panels will no longer conform to 3.2 to 3.4.3.2 Mode of fragmentationWhen tested in accordance with
20、annex a, a sample of glass panel of not less than 76 mm 76 mm, which is uninterrupted by holes, shall fragment in such a way that the number of particles counted in a 50 mm 50 mm area shall be not less than 60.NOTE The purpose of this test is to determine whether the glass has been adequately toughe
21、ned.3.3 Resistance to thermal shockWhen tested in accordance with in annex B, glass panels shall not fracture.3.4 Resistance to impactWhen tested in accordance with annex C, flat glass panels that include a 300 mm 300 mm area, which is uninterrupted by holes, shall not fracture.NOTE A reliable test
22、method has not been developed yet to allow this test requirement to be applied to glass panels that have a curved profile.4 MarkingGlass panels shall be marked or labelled with, or a declaration shall be given by the manufacturer with respect to, the following information:the number and date of this
23、 British Standard, i.e. BS 3193:2008;a) 1)the manufacturers identification or trade mark.b) 1)Marking BS 3193:2008 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the stan
24、dard. the accuracy of the claim is solely the claimants responsibility. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BritiSh Standard BSI 2008 3BS 3193:2008Annex A (normative) Fragmentation test methodA.1 Principlea supported glas
25、s panel is shattered, the number of particles within a specified area are counted and the results are recorded.A.2 ProcedureSupport the glass panel over its whole area and ensure that particles will not be scattered upon fragmentation. if the fragmentation test is to be conducted on curved glass, su
26、pport the sample to maintain the shape of the panel.Shatter the glass with a centre punch placed 13 mm in from the midpoint of one of the longer edges of the glass. Within five minutes of fracture and without using any aid to vision (except spectacles if normally worn) count the particles in a 50 mm
27、 50 mm area located approximately at the centre of the area of coarsest fracture and excluding an area within 13 mm of any edge or hole.a suitable method of counting the particles is to place over the glass a square of transparent material of 50 mm side and mark a spot of ink as each particle within
28、 the square is counted. to count particles at the edge of the square, select any two adjacent sides of the square and count all the particles intersected by these. Exclude all other intersected particles. record the particle count obtained.BS 3193:20084 BSI 2008BritiSh StandardAnnex B (normative) Th
29、ermal shock testB.1 Principlea glass panel is heated and rapidly cooled, and any damage to the panel is recorded.Each test is performed on a new glass panel. in the case of asymmetric glass panels (see 2.3) the thermal shock test is performed on both sides, using separate glass panels.B.2 Procedureh
30、eat the glass panel to a temperature of 185 C 5 C throughout and immediately quench it with a stream of water at a temperature that gives a temperature differential of 165 C.direct the cold water onto a central part of the panel from a 5 mm 0.2 mm internal diameter tube, the end of which is 150 mm 2
31、 mm above the centre of the horizontal test panel. Use at least 1 L of cold water at a rate of 10 mL/s to 15 mL/s. record whether the panel fractures.BritiSh Standard BSI 2008 5BS 3193:2008Annex C (normative) Impact testC.1 Principlea loaded vessel is dropped 10 times in succession onto a glass pane
32、l, and any damage to the panel is recorded. in the case of asymmetric glass panels (see 2.3) the impact test is performed on both sides using separate glass panels.C.2 ApparatusC.2.1 A loaded vessel, having a bottom of copper or aluminium, which is flat over a diameter of 120 mm 10 mm and has edges
33、rounded to a radius of at least 10 mm, uniformly filled with sand or shot so that the total mass of the vessel plus sand or shot is at least 1.8 kg.C.2.2 A means of dropping the vessel flat, from a height of 150 mm 2 mm, measured from the bottom of the vessel to the upper surface of the glass panel.
34、C.2.3 Supporting fixture, as shown in Figure C.1, composed of two steel frames, with machined borders, fitting one over the other and faced with rubber gaskets of hardness 50 10 irhd (Shore hardness a.50). the upper frame shall have a mass of 3 kg 0.5 kg. the lower frame shall rest on a steel box th
35、at collects the broken glass and vessel should the panel break; the lower frame is separate from the box for maintenance purposes but this is not essential. the steel box on which the lower frame rests shall be welded onto a sheet of steel resting on a sheet of rubber of hardness 50 10 irhd placed o
36、n a rigid base, e.g. a substantial concrete base.C.3 ProcedureCondition the glass panel at 20 C 5 C for at least 4 h immediately preceding the test.Place the glass panel between the upper and lower frames of the apparatus; ensure that the plane of the panel is perpendicular 3 to the incident directi
37、on of the vessel. release the vessel so that the point of impact of the centre of its base is within 25 mm of the centre of the test piece.impact each glass panel 10 times in succession. record whether the panel fractures and stop the test if it fractures before 10 impacts have been completed.BS 319
38、3:20086 BSI 2008BritiSh StandardFigure C.1 Support for glass panels in the impact testall dimensions are in millimetres. Only critical dimensions are toleranced.ABCDEF( 290 )260 + 1_ 15 + 1_23 + 2_23 + 2_1503 1210_350KeyUpper framea Glass panelB Lower frameC rubber gasketsd BoxE rubberF BritiSh Stan
39、dard BSI 2008 7BS 3193:2008Annex D (informative) Guidance for manufacturers of domestic appliances on the use of glass panelsManufacturers using glass panels in domestic appliances should observe the following recommendations.Where panels are hinged onto holes drilled in the glass, the a) distance b
40、etween the edge of the glass and the edge of the hole should be not less than 1.5 times the thickness of the glass.the hole should be bushed with nonmetallic material in order to b) prevent the hinge fixings from damaging the glass inside the hole during assembly or during subsequent customer usage,
41、 which can cause early fragmentation of the glass panel.all sharp edges and corners should be dressed.c) rigid contact between metal and glass should be avoided especially d) when glass panels are likely to be subject to thermal stresses.the method used to hold glass panels in appliances should not
42、e) produce additional stress in the panels over the temperature range they could encounter. allowance should be made for any difference in coefficients of thermal expansion of the glass and its support, by permitting movement of one in relation to the other.When designing an appliance, manufacturers
43、 should minimize f) thermal gradients that could arise in the glass panel during use of the appliance.appliances should be designed such that the temperature of g) the panel is not allowed to exceed 300 C to ensure that the characteristics of the glass do not change.NOTE In normal use toughened glas
44、s can be expected to withstand temperatures up to 300 C.appliance manufacturers should state in their appliance h) operating instructions that harsh abrasive cleaners and sharp metal scrapers should not be used, as they can scratch the glass surface and result in premature failure.Suitable thermal s
45、hock and impact tests should be performed i) on the panel installed in the appliance, to ensure that the safety characteristics of the glass are not detrimentally affected by the design of the appliance.Wherever possible, notches, cutouts and sudden major changes j) in shape, e.g. Figure d.1, should
46、 be avoided as they can create areas of high local stress that might result in premature failure of the glass panel.BS 3193:20088 BSI 2008BritiSh StandardFigure d.1 Sudden major changes in shapeBritiSh Standard BSI 2008 9BS 3193:2008Annex E (informative) Guidance on handling glassto prevent damage t
47、o glass panels between the glass processor and the appliance manufacture, individual glass panels are interleaved with a protective material to avoid scratching.Glass panels need to be transported vertically in suitable containers with additional protection to protect the edges of the panels. applia
48、nce manufacturers need to ensure the glass panels are stored vertically and are protected until final assembly.Glass panels need to be handled carefully during the assembly process so that edges are not damaged. Jigs and fixtures have to be suitably lined so as to prevent contact between the glass p
49、anel and metal parts of the jigs and fixtures.Workbenches have to be kept clean to ensure that the glass panel is not scratched during the assembly process by sharp debris accumulated on the workbench, e.g. metal swarf and loose screws.Glass panels have to be stored vertically and interleaved with protective material. When transporting glass panels they need to be protected and secured.Packaging of the final product needs to ensure that any clamping pressure from the handling system is not transmitted on
