BS 5416-1990 Specification for china tableware《瓷餐具规范》.pdf

1、BRITISH STANDARD BS 5416:1990 Specification for China tableware UDC 642.72 033.62:666.51/.52:666.64:532.696.52:620.11:006.3/.8BS5416:1990 This British Standard, having been prepared under the directionof the Furniture and Household Equipment StandardsPolicy Committee, waspublished under the authorit

2、yof the Board of BSI andcomes into effect on 30April1990 BSI 08-1999 First published October 1976 Second edition April 1990 The following BSI references relate to the work on this standard: Committee reference FHM/29 Draft for comment 89/39907 DC ISBN 0 580 18354 8 Committees responsible for this Br

3、itish 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 Br

4、itish 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 (

5、Consumer 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 CommentsBS5416:1990 BSI 08-1999 i Contents Page Committees re

6、sponsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Sampling 1 4 Performance 2 5 Marking 2 Appendix A Method of test for the determination of water absorption 3 Appendix B Method of test for the determination of translucency 4 Table 1 Sample size for testing 1BS5416:1990 ii BSI 08-1

7、999 Foreword This revision of BS5416 has been prepared under the direction of the Furniture and Household Equipment Standards Policy Committee. It supersedes BS5416:1976 which is withdrawn. There is a wide variety of terms used to describe different types of ceramic tableware, many of which are not

8、well understood. An important class of product is that characterized by low water absorption and a degree of translucency generally known as china in the UK and as porcelain elsewhere. For the purpose of this British Standard the terms “china” and “porcelain” are taken as being synonymous. Bone chin

9、a is a particular type of china which fulfils the requirements set out in this standard but which has, in addition, a distinctive chemical composition which enables it to be precisely identified whenever necessary. This standard specifies the two principal technical requirements that need to be fulf

10、illed before a product can correctly be called china or porcelain viz. transluency and water absorption, 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 an

11、y other aspects of fitness to purpose. It does not include 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 Instrument1988 No.1647 The Ceramic Ware (Safety) Regulati

12、ons1988 which limits the amount of lead and cadmium which may be released from ceramic ware for contact with food. Product certification. Users of this British Standard are advised to consider the desirability of third party certification of product conformity with this British Standard based on tes

13、ting and continuing surveillance, which may be coupled 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 ce

14、rtification scheme does not already exist, users should 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.

15、Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 4 and a back cover. This standard has been updated (see copyright date) and may have had amendments i

16、ncorporated. This will be indicated in the amendment table on the inside front cover.BS5416:1990 BSI 08-1999 1 1 Scope The British Standard specifies requirements for resistance to water absorption and transluency for china tableware which determine that the description is applied correctly to the p

17、roduct. Compliance is determined by testing a representative 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 gene

18、rally made from a mixture of clays and other materials 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 china tableware composed of a hard and translucent ceramic, with low wate

19、r absorption including hard porcelain, soft porcelain, biscuit porcelain (including parian) and bone china 2.4 hard porcelain china made from a body composed of kaolin, quartz, feldspar and sometimes calcium carbonate. After an initial low temperature firing, it is normally covered with a colourless

20、 transparent glaze fired at the same time as the body and thus fused together with it 2.5 soft porcelain china usually containing less alumina but more silica and fluxes than hard porcelain 2.6 biscuit porcelain unglazed porcelain 2.7 parian ware fine-grained unglazed porcelain containing more felds

21、par than hard porcelain, often resembling Paros marble in appearance 2.8 bone china china containing at least35% by mass of the fired body of tricalcium orthophosphate, traditionally in the form of bone ash, which gives a translucent body at a lower firing temperature than is the case with hard porc

22、elain 2.9 biscuit unglazed body of ceramic ware 2.10 consignment number of items supplied in response to a single order 2.11 water absorption capacity of a ceramic body to absorb water 2.12 translucency ability of a ceramic body to transmit a proportion of the light incident upon it 3 Sampling Sampl

23、es 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 than50 samples shall be taken from any one consignment. Table 1 Sample size for testing No. of items in consignment

24、Minimum sample size 2 to 10 11 to 100 101 to 500 501 to 1000 1001 to 2500 2501 to 5000 5001 to 10000 10000 1 3 5 10 15 20 25 35BS5416:1990 2 BSI 08-1999 4 Performance 4.1 Water absorption When tested in accordance withAppendix A, the average value for water absorption for all samples tested shall no

25、t exceed0.2%. Additionally, when tested in accordance withAppendix A, the following shall apply for specific sample sizes. a) For a sample size not exceeding10 items, no item tested shall give an individual value for water absorption exceeding0.4%. b) For a sample size between11 and25 items, not mor

26、e 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 the items tested shall give an individual value for water absorption exceeding0.4%. d) For a sample size between36 and50 items, not more

27、than three of the items tested shall give an individual value for water absorption exceeding0.4%. 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 be determined on th

28、e cumulative results of all tests performed. 4.2 Translucency When tested in accordance withAppendix B, the average ratio of the intensity of the light transmitted through the sample to the intensity of the incident light, for all items tested shall exceed0.75% for a sample thickness of2.00mm. NOTEA

29、s it is not possible to grind a specimen accurately to a thickness of2.00mm, specimens are ground to a series of thicknesses on either side of this value and the transluency at2.00mm determined by interpolation. 5 Marking Each item of china tableware complying with this standard shall be marked with

30、 the following. a) The name, trade mark or any other means of identifying the U K manufacturer or responsible supplier. b) The number of this British Standard, i.e.BS5416 1) . NOTEThe date of the standard, or the manufacturers own marking of the date of manufacture (such that it is distinct from the

31、 date of the standard) may also be included. c) The word “China” or “Porcelain”. NOTEAdditional descriptors, in accordance with the definitions given in2.3 to2.8 may also be included. 1) Marking BS5416 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim b

32、y or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy 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 desira

33、ble.BS5416:1990 BSI 08-1999 3 Appendix A Method of test for the determination of water absorption A.1 Principle The water absorption (see2.11) of china tableware is assessed as the increase in mass which a prepared test piece undergoes as a result of controlled immersion in water, expressed as a per

34、centage of the mass of the dry test piece. A.2 Apparatus A.2.1 Air-circulating oven, capable of maintaining a temperature of110 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 wh

35、ich boiling of the test pieces in water may take place. A.2.5 Source of heat A.2.6 De-gassed distilled 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 and2

36、0g in mass from areas of the broken sample as follows. a) For flatware, take one test piece from the 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 Proc

37、edure Dry the test pieces to constant mass in an air-circulating oven maintained at110 5 C. Cool the 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 th

38、erein to2.5 1.5kPa and maintain at this pressure for60 5min. Without admitting air, admit de-gassed distilled 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 b

39、oil the water and test pieces for605min ensuring that the test pieces remain fully submerged. Allow the 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

40、glazed surfaces are completely dry and broken surfaces retain a thin film of moisture appearing as a 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

41、 of the test piece from the following formula: where Report the individual results and the arithmetic 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

42、-BS5416:1990 4 BSI 08-1999 Appendix B Method of test for the determination of translucency B.1 Principle The translucency (see2.7) of china tableware is assessed as the ratio of the intensity of light transmitted through a sample to the intensity of light incident upon it, expressed as a percentage

43、for a sample thickness of2mm. B.2 Apparatus B.2.1 Photometer, having a light source capable of emitting white light of colour temperature approximately3400K. NOTEThe photometer should provide incident light in the form of a parallel beam normal to the surface of the test piece and all transmitted li

44、ght should be collected; the use of an instrument incorporating an integrating sphere is commended as a means of achieving the latter. B.2.2 Uniform reference specimens, of accurately known translucency in the region of0.75%. B.3 Sample preparation Cut five discs, of a size corresponding to the size

45、 of the sample holder of the photometer to be used (seeB.2.1), from the sample. Grind away the glaze on each side of each disc to provide test pieces of approximate thicknesses2.5, 2.25, 2.0, 1.75 and1.5mm with parallel unglazed faces. B.4 Procedure By means of the photometer (B.2.1) determine and r

46、ecord the percentage transmission of white light, of colour temperature approximately3400K, through each test piece and through the uniform reference specimens (B.2.2). Measure and record the thickness of each test piece to the nearest0.01mm. B.5 Calculation and expression of results Construct a gra

47、ph of percentage transmission versus thickness for the five test pieces examined. By interpolation, determine the translucency ofthesample for a test piece thickness of precisely2.00mm. Correct the value obtained by the photometer factor determined by the results obtained from the uniform reference

48、specimens.blankBS 5416:1990 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 Charter. Rev

49、isions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers membe