1、BRITISH STANDARD BS 2782-6: Method 631A: 1993 ISO 4591:1992 Methods of testing Plastics Part 6: Dimensional properties Method 631A: Determination of gravimetric thickness and yield of flexible sheet IMPORTANT NOTE. Before reading this method it is essential to read BS2782-0, Introduction, issued sep
2、arately. UDC 678.5/.8 416:678.01:531.717.1BS 2782-6:Method 631A:1993 This British Standard, having been prepared under the directionof the Plastics and Rubber Standards Policy Committee, was published underthe authority of the Standards Board and comes into effect on 15March1993 BSI07-1999 First pub
3、lished January1982 Second edition March1993 The following BSI references relate to the work on this standard: Committee reference PRM/75 Draft for comment 91/43649 DC ISBN 0 580 21658 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Pla
4、stics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/75, upon which the following bodies were represented: British Plastics Federation Her Majestys Stationery Office Institute of Trading Standards Administration Ministry of Defence Packaging and Industrial Films Association
5、 PIRA International Amendments issued since publication Amd. No. Date CommentsBS 2782-6:Method 631A:1993 BSI 07-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Determination of gravimetric thickness of a sample 1 4 Determinatio
6、n of average gravimetric thickness and yield of a roll 2 List of references Inside back coverBS 2782-6:Method 631A:1993 ii BSI 07-1999 National foreword This British Standard has been prepared under the direction of the Plastics and Rubber Standards Policy Committee and is identical with ISO4591:199
7、2 Plastics Film and Sheeting Determination of average thickness of a sample, and average thickness and yield of a roll, by gravimetric techniques (gravimetric thickness) published by the International Organization for Standardization (ISO). This standard supersedes BS2782:Method631A:1982 which is wi
8、thdrawn. 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 itself confer immunity from legal obligations. Cross-references International s
9、tandard Corresponding British Standard ISO 1183:1987 BS2782 Methods of testing plastics Methods620A to620D:1991 Determination of density and relative density of non-cellular plastics (Identical) ISO 4592:1992 Method 632A:1993 Determination of length and width of flexible sheet (Identical) Summary of
10、 pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 and 2, an inside back cover 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 table on the inside front co
11、ver.BS 2782-6:Method 631A:1993 BSI 07-1999 1 1 Scope This International Standard specifies a method for the determination of the gravimetric thickness of a sample of plastics film or sheeting (see clause3); a method for the determination of the average gravimetric thickness and, if required, the yie
12、ld (area per unit mass) of a roll of plastics film or sheeting (see clause4). These methods are applicable to all plastics films and sheeting, and have special value when mechanical scanning is not sufficiently precise, particularly for measuring the thickness of embossed sheeting. 2 Normative refer
13、ences The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International St
14、andard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1183:1987, Plastics Methods for determining the density and relative density of non-ce
15、llular plastics. ISO 4592:1992, Plastics Film and sheeting Determination of length and width. 3 Determination of gravimetric thickness of a sample 3.1 Principle The gravimetric thickness of a sample is calculated from measurements of its mass, area and density. 3.2 Apparatus 3.2.1 Knife-edged punch,
16、 square or circular, having an area of100cm 2 0,5 cm 2 , or 3.2.2 Square template, having an area of100cm 2 0,5cm 2 . 3.2.3 Balance, accurate to0,0001g. 3.3 Specimens Specimens of area100cm 2 0,5cm 2shall be cut at positions approximately equally spaced across the width of the sample in each of two
17、bands approximately 1m apart in the longitudinal direction. The minimum number of specimens taken from each band across the film or sheeting shall be dependent on the width of the sample as follows: In the case of very thin film, when the mass of a specimen of area100cm 2 0,5cm 2is less than 1g, two
18、 specimens located very close together on the film in the longitudinal (extrusion/calender) direction shall be used for one measurement. 3.4 Procedure 3.4.1 Determine the mass, in grams, of the specimen to at least three significant figures, and its density in accordance with ISO1183, at a temperatu
19、re of23 C 1 C. Take care to prevent the formation of static charges which could affect the reproducibility of this determination of mass. 3.4.2 For moisture-sensitive film or sheeting, the conditioning requirements of time and relative humidity shall be agreed between the buyer and seller. 3.5 Expre
20、ssion of results Calculate the gravimetric thickness, t s , in micrometres or millimetres, from equation (1) or (2) respectively, when one specimen is used: where When two specimens are used, use equation (3) or(4): widths smaller than or equal to1000mm 3 widths greater than 1000mm and up to1500 mm
21、5 widths greater than1500mm 10 . . . (1) . . . (2) m s is the mass, in grams, of the specimen; is the density, in grams per cubic centimetre, of the specimen. . . . (3) . . . (4) t s 100 m s - 4m () = t sm s 10 - mm () = t s 50 m s - 4m () = t s m s 20 - mm () =BS 2782-6:Method 631A:1993 2 BSI 07-19
22、99 3.6 Precision The precision of this test method is not known because inter-laboratory data are not available. When inter-laboratory data are obtained, a precision statement will be added in the subsequent revision. 3.7 Test report The test report shall include the following information: a) a refe
23、rence to this International Standard; b) all information necessary for the complete identification of the sample; c) gravimetric thickness of each specimen, in micrometres or millimetres; d) arithmetic mean of the test results, to the nearest 14m, or0,001mm, reported as the average gravimetric thick
24、ness of the sample. 4 Determination of average gravimetric thickness and yield of a roll 4.1 Principle The average thickness and, if required, the yield of a roll are calculated from measurements of the length, average width and net mass of the roll and of the density of the film or sheeting. 4.2 Ap
25、paratus 4.2.1 Weighing device, the accuracy of which is at least0,5% of the reading. 4.3 Procedure 4.3.1 Length and average width of film or sheeting in a roll Determine the length and average width of the roll, in metres, in accordance with ISO4592. 4.3.2 Net mass of roll Place the roll of material
26、 centrally on the pan or other support of the weighing device. Ensure that the roll of material and the pan are free from contact with other bodies. Determine the gross mass to an accuracy of0,5%. Deduct the mass of the tube, or other object onto which the film or sheeting has been rolled, from the
27、gross mass to give the net roll mass, with the same accuracy. Determine the net roll mass, in kilograms, to the nearest significant figure corresponding to an accuracy of 0,5 %. 4.3.3 Density Determine the density of the film or sheeting in accordance with ISO1183, at 23 C 1 C. 4.4 Expression of res
28、ults 4.4.1 Average gravimetric thickness of roll Calculate the average gravimetric thickness of the roll, t r , in micrometres or millimetres, from equation(5) or (6) respectively: where Express the result to the nearest 14m or0,001mm respectively, 4.4.2 Yield (area per unit mass) If required, calcu
29、late the yield, A m , in square metres per kilogram, from equation (7): where L, b and m rare as defined in4.4.1. 4.5 Precision The precision of this test method is not known because inter-laboratory data are not available. When inter-laboratory data are obtained, a precision statement will be added
30、 in the subsequent revision. 4.6 Test report The test report shall include the following information: a) a reference to this International Standard; b) all information necessary for the complete identification of the material; c) average gravimetric thickness of the tested roll; d) yield of the roll
31、 (if required). . . . (5) . . . (6) m r is the net mass, in kilograms, of the roll; L is the length, in metres, of the roll; b is the average width, in metres, of the roll; is the density, in grams per cubic centimetre, of the film or sheeting. (7) t r 1000 m r Lb - 4m () = t rm r Lb - mm () = A m L
32、b m r - =BS 2782-6:Method 631A:1993 BSI 07-1999 List of references See national foreword.BS 2782-6: Method 631A: 1993 ISO 4591:1992 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the
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