BS 4034-1990 Specification for vitrified hotelware《上釉餐具规范》.pdf

1、BRITISH STANDARD BS 4034:1990 Specification for Vitrified hotelware UDC 642.72:666.51/.52:666.64:532.696.52:620.11:006.3/.8BS4034:1990 This British Standard, having been prepared under the directionof the Furniture and Household Equipment StandardsPolicy Committee, waspublished under the authorityof

2、 the Board of BSI andcomes into effect on 30April1990 BSI 08-1999 First published June 1966 Second edition April 1990 The following BSI references relate to the work on this standard: Committee reference FHM/29 Draft for comment 89/39906 DC ISBN 0 580 18349 1 Committees responsible for this British

3、Standard The preparation of this British Standard was entrusted by the Furniture and Household Equipment Standards Policy Committee (FHM/-) to Technical Committee FHM/29, upon which the following bodies were represented: Association of Metropolitan Authorities Association of Public Analysts British

4、Ceramic Gift and Tableware Manufacturers Association British Ceramic Manufacturers Federation British Ceramic Research Ltd. British Glass Manufacturers Confederation British Vitrified Hotelware Association Consumer Policy Committee of BSI Department of Health Department of Trade and Industry (Consum

5、er Safety Unit, CA Division) Institute of Trading Standards Administration Institute of Vitreous Enamellers Stoneware Potters Association Vitreous Enamel Development Council Amendments issued since publication Amd. No. Date of issue CommentsBS4034:1990 BSI 08-1999 i Contents Page Committees responsi

6、ble Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Sampling 1 4 Performance 1 5 Marking 2 Appendix A Method of test for the determination of water absorption 3 Appendix B Method of test for the determination of crazing 4 Table 1 Sample size for testing 1BS4034:1990 ii BSI 08-1999 Forewor

7、d This revision of BS4034 has been prepared under the direction of the Furniture and Household Equipment Standards Policy Committee. It supersedes BS4034:1966 which is withdrawn. There is a wide variety of terms used to describe different types of ceramic tableware, many of which are not well unders

8、tood. An important class of product is that characterized by low water absorption and resistance to crazing generally known as vitrified hotelware and this standard specifies the two principal technical requirements that need to be fulfilled before a product can correctly be called vitrified hotelwa

9、re viz. resistance to water absorption and crazing, determined by sampling from a consignment. It does not purport to have any relevance in the field of technical or industrial ceramics such as sanitary or electrical ceramics, nor does it cover any other aspects of fitness for purpose. It does not i

10、nclude any requirements for those characteristics which are matters of personal choice or which can be readily assessed by the purchaser at the point of sale. Attention is drawn to Statutory Instrument 1988 No. 1647 The Ceramic Ware (Safety) Regulations 1988 which limits the amount of lead and cadmi

11、um which may be released from ceramic ware for contact with food. Product certification. Users of this British Standard are advised to consider thedesirability of third party certification of product conformity with this BritishStandard based on testing and continuing surveillance, which may be coup

12、led with assessment of a suppliers quality systems against the appropriate Part of BS5750. Enquiries as to the availability of third party certification schemes will be forwarded by BSI to the Association of Certification Bodies. If a third party certification scheme does not already exist, users sh

13、ould consider approaching an appropriate body from the list of Association members. 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 itse

14、lf confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment t

15、able on the inside front cover.BS4034:1990 BSI 08-1999 1 1 Scope This British Standard specifies requirements for resistance to water absorption and crazing for vitrified hotelware which determine that the description is applied correctly to the product. Compliance is determined by testing a represe

16、ntative sample taken from a consignment. 2 Definitions For the purposes of this British Standard the following definitions apply. 2.1 types of tableware cups, saucers, plates, bowls, dishes, jugs, tea-pots and coffee-pots 2.2 ceramic material generally made from a mixture of clays and other material

17、s distinguished from glass and glass ceramic by the fact that it is first shaped and then rendered permanent by firing at a temperature generally well in excess of1000 C 2.3 vitrified hotelware tableware composed of a vitrified ceramic body covered with glaze and resistant to water absorption and cr

18、azing 2.4 biscuit unglazed body of ceramic ware 2.5 consignment number of items supplied in response to a single order 2.6 water absorption capacity of a ceramic body to absorb water 2.7 crazing fine cracks which can be seen in the surface of glazed ceramic tableware but which do not penetrate the b

19、ody 3 Sampling Samples for testing shall be taken at random from a consignment in accordance withTable 1 and shall be representative of all of the types of tableware included in the consignment. Not more than50samples shall be taken from any one consignment. 4 Performance 4.1 Water absorption When t

20、ested in accordance withAppendix A, the average value for water absorption for all samples tested shall not exceed0.2%. Additionally, when tested in accordance withAppendix A, the following shall apply for specific sample sizes. Table 1 Sample size for testing a) For a sample size not exceeding10ite

21、ms, no item tested shall give an individual value for water absorption exceeding0.4%. b) For a sample size between 11 and25items, not more than one of the items tested shall give an individual value for water absorption exceeding0.4%. c) For a sample size between26 and35 items, not more than two of

22、the items tested shall give an individual value for water absorption exceeding0.4%. d) For a sample size between36 and50items, not more than three of the items tested shall give an individual value for water absorption exceeding0.4%. Number of items inconsignment Minimum sample size 2 to10 11 to100

23、101 to500 501 to1 000 1 001 to2 500 2 501 to5 000 5 001 to 10000 10000 1 3 5 10 15 20 25 35BS4034:1990 2 BSI 08-1999 If the criteria for compliance are not met at the minimum sampling level then it shall be permissible for further samples, to a maximum total of50, to be tested and for compliance to

24、be determined on the cumulative results of all tests performed. 4.2 Crazing When tested in accordance withAppendix B, no item tested shall exhibit crazing when examined as described inB.5. 5 Marking Each item of vitrified hotelware complying with this standard shall be marked with the following. a)

25、The name, trade mark or any other means of identifying the UK manufacturer or responsible supplier. b) The number of this British Standard, i.e.BS4034 1) . NOTEThe date of the standard, or the manufacturers own marking of the date of manufacture (such that it is distinct from the date of the standar

26、d) may also be included. c) The word(s) “Vitrified” or “Vitrified hotelware”. 1) Marking BS4034 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 standard. The accuracy

27、of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS4034:1990 BSI 08-1999 3 Appendix A Method of test for the determination of water absorption A.1 Pri

28、nciple The water absorption (see2.6) of vitrified hotelware is assessed as the increase in mass which a prepared test piece undergoes as a result of controlled immersion in water, expressed as a percentage of the mass of the dry test piece. A.2 Apparatus A.2.1 Air-circulating oven, capable of mainta

29、ining a temperature of 110 5 C. A.2.2 Desiccator A.2.3 Balance, capable of determining masses of between5g and20g to an accuracy of0.001g. A.2.4 Vessel, from which air can safely be removed and in which boiling of the test pieces in water may take place. A.2.5 Source of heat A.2.6 De-gassed distille

30、d or de-gassed de-ionized water A.2.7 Smooth cotton cloth A.3 Test pieces Immediately before commencement of the test procedure break the sample, by impact, and take two test pieces of between5g and20g in mass from areas of the broken sample as follows. a) For flatware, take one test piece from the

31、central area and the second test piece from the rim area of the sample. b) For holloware, take one test piece from the top section and the second test piece from the base area of the sample. A.4 Procedure Dry the test pieces to constant mass in an air-circulating oven maintained at110 5 C. Cool the

32、test pieces in a desiccator (A.2.2) to ambient temperature. Weigh the test pieces and record their masses to the nearest0.001g. Place the dry test pieces into a vessel (A.2.4), reduce the pressure therein to2.5 1.5kPa and maintain at this pressure for60 5min. Without admitting air, admit de-gassed d

33、istilled or de-gassed de-ionized water (A.2.6) at ambient temperature to the vessel, until the test pieces are fully covered. Then admit air to the vessel, returning it to atmospheric pressure, and boil the water and test pieces for605min ensuring that the test pieces remain fully submerged. Allow t

34、he test pieces to cool for not less than24h whilst remaining submerged in the boiled water. Remove the test pieces from the water and wipe them with a moistened smooth cotton cloth (A.2.7) such that glazed surfaces are completely dry and broken surfaces retain a thin film of moisture appearing as a

35、sheen. Weigh each test piece and record their masses to the nearest0.001g. A.5 Calculation and expression of results For each test piece calculate the water absorption as a percentage of the dry mass of the test piece from the following formula: where Report the individual results and the arithmetic

36、 mean of the two results obtained for each sample. W 1 is the mass of the test piece after drying to constant mass (in g). W 2 is the mass of the test piece after immersion (in g). 100W 2 W 1 () W 1 -BS4034:1990 4 BSI 08-1999 Appendix B Method of test for the determination of crazing B.1 Principle T

37、he crazing (see2.7) of vitrified hotelware is assessed by subjecting a prepared sample to steam under pressure, then examining the glaze of the cooled sample for crazing with the assistance of a staining agent. B.2 Apparatus B.2.1 Vessel, which can be sealed and safely pressurized with steam. B.2.2

38、Staining agent, consisting of a solution of51g/L eosin and51g/L domestic washing-up liquid. B.2.3 Soft cotton cloth B.3 Sample preparation Grind three separate circles of diameter12.5 2.5mm into the surface of the complete sample, evenly distributed across the sample, such that the glaze is penetrat

39、ed and the biscuit exposed over the entire area of these circles. B.4 Procedure Place the sample into a vessel (B.2.1) in a position where the sample is protected from direct contact with incoming steam and cannot contact any standing water which may result from steam condensation. Seal the vessel a

40、nd raise the pressure therein, by means of steam injection, to a maximum pressure of340 10kPa and maintain at this pressure for161h. Reduce the pressure in the vessel to atmospheric pressure, by release of steam. Remove the sample and allow it to cool naturally to ambient temperature. Immerse the sa

41、mple completely in the staining agent (B.2.2) for5 1min and then dry it by wiping with a soft cotton cloth (B.2.3). B.5 Assessment of samples Examine the sample for crazing, exhibited as stained line markings within the glaze.5 blankBS 4034:1990 BSI 389 Chiswick High Road London W4 4AL BSIBritishSta

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