BS 4747-2-1995 Methods for determination of saleable mass in lots of pulp - Pulps (such as flash-dried pulps) baled in slabs《分包纸浆销售质量测定方法 第2部分 厚板打包纸浆(如快速干燥纸浆)》.pdf

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1、BRITISH STANDARD BS 4747-2: 1995 ISO 801-2: 1994 Methods for Determination of saleable mass, in lots, of pulp Part 2: Pulps (such as flash-dried pulps) baled in slabsBS4747-2:1995 This British Standard, having been prepared under the directionof the Materials andChemicals Sector Board (I/-),was publ

2、ished under the authority of the Standards Board and comes into effect on 15 January 1995 BSI 11-1999 First published September 1980 Second edition January 1995 The following BSI references relate to the work on this standard: Committee reference PAI/11 Draft for comment 91/45546 DC ISBN 0 580 23646

3、 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PAI/11, upon which the following bodies were represented: British Carton Association British Fibreboard Packaging Association British Printing Industries Federation Briti

4、sh Textile Confederation Envelope Makers and Manufacturing Stationers Association Her Majestys Stationery Office Institute of Paper Conservation Paper Federation of Great Britain Pira International Post Office University of Manchester (Institute of Science and Technology) Coopted members Amendments

5、issued since publication Amd. No. Date CommentsBS4747-2:1995 BSI 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle 2 5 Apparatus 2 6 Sample bales 6 7 Procedure 6 8 Expression of results

6、 7 9 Test report 8 Annex A (informative) Example of a full certificate of analysis and related calculations 9 Annex B (informative) Report on investigations 12 Figure 1 Cutting tool 2 Figure 2 Cutting tool in use 3 Figure 3 The random card system 4 Figure 4 Sample selection by the random card system

7、 5 Table 1 Number of sample bales to be taken 6 List of references Inside back coverBS4747-2:1995 ii BSI 11-1999 National foreword This Part of BS4747 has been prepared by Technical Committee PAI/11, Methods of test for paper, board and pulp. It is identical with ISO801-2:1994 Pulps Determination of

8、 saleable mass in lots Part2: Pulps (such as flash-dried) baled in slabs, published by the International Organization for Standardization (ISO). This edition supersedes BS4747-2:1980 which is withdrawn. A British Standard does not purport to include all the necessary provisions of a contract. Users

9、of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-reference International Standard Corresponding British Standard ISO 801-1:1994 BS 4747 Methods for determination of saleable mass, i

10、n lots, of pulp Part 1:1995 Pulp baled in sheet form Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This

11、will be indicated in the amendment table on the inside front cover.BS4747-2:1995 BSI 11-1999 1 Introduction The extreme difficulty encountered in the cutting of wedges from thick slabs of pulp, such as flash-dried pulp, for which this test method has been designed, has led to the adoption of a disc

12、sampling procedure, following an extensive investigation (practical and statistical) of the problem. A brief statement of this investigation is given inAnnex B. It is recognized that, although the wedge system of sampling is, in theory, more accurate than the disc system, the drilling procedure spec

13、ified in this part of ISO801 may be regarded as satisfactory because, in practice, the moisture variation from place to place is relatively small (for example in flash-dried pulps). 1 Scope This part of ISO801 specifies a method for determining the dryness of a lot of pulp baled in slabs and for cal

14、culating its saleable mass. This method is applicable to most kinds of pulp, in bales of approximately200kg, and made up of four to six slabs or wads, of fairly uniform and similar thickness. It may also be applicable to bales not composed of individual layers, but which are naturally delaminateable

15、. It does not apply to pulp baled in sheet form or to pulp in unitized bales. The method is not applicable if the drilling device becomes appreciably hot because of frictional heat evolved during drilling; this can occur with some strong chemical or semichemical pulps. An example of a full certifica

16、te of analysis and related calculations is given inAnnex A. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this part of ISO801. At the time of publication, the edition indicated was valid. All standards are subject to

17、revision, and parties to agreements based on this part of ISO801 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 801-1:, Pulps Determination of

18、 saleable mass in lots Part1: Pulp baled in sheet form 1) . 3 Definitions For the purposes of this part of ISO801, the following definitions apply. 3.1 lot the total number of bales of the same sort of pulp of specific characteristics the number of bales comprising a lot is indicated by the invoice

19、or by agreement between the interested parties a lot of bales of pulp is said to be “with specification” if it is accompanied by a certificate of origin stating for each bale either its gross mass (3.2) and its absolute dryness(3.4), or its saleable mass (3.7). 3.2 gross mass the total mass of a bal

20、e, a part of a lot or a lot comprising contents; wrappers (pulp paper); packaging wires or strappings. 3.3 oven-dry mass the mass obtained on drying pulp at105 C 2 C, until constant mass is reached 3.4 absolute dryness the ratio of the oven-dry mass (3.3) of the pulp to its initial mass, expressed a

21、s a percentage 3.5 air-dry mass the mass of the pulp when its moisture content is in equilibrium with the ambient atmosphere 3.6 theoretical commercial dryness a conventional equilibrium value of88% or90% according to the country and/or commercial agreements 2) 1) To be published. (Revision of ISO80

22、1-1:1979) 2) If the air dryness is90%, the pulp contains90parts by mass of absolutely dry fibres and10parts by mass of water. For an air dryness of88%, the corresponding Figures are88 and12.BS4747-2:1995 2 BSI 11-1999 3.7 saleable mass the gross mass (3.2) multiplied by the absolute dryness (3.4) di

23、vided by the theoretical commercial dryness (3.6). Usually, it approximates to the air-dry mass (3.5) 3.8 invoiced mass the saleable mass (3.7) indicated by the vendor on the invoice 4 Principle Sample bales are taken from the lot in number which is a function of the total number of bales and slabs

24、in the complete lot and in accordance with a sliding scale. The sample bales are weighed individually and collected in groups containing equal numbers of bales. A disc-shaped test piece is cut from every lap or wad. The test pieces are weighed and dried to constant mass to determine their oven-dry m

25、ass. The saleable mass of the lot is then calculated. 5 Apparatus 5.1 Scale, suitable for weighing the bales to an accuracy of at least1/1000. 5.2 Balance, suitable for weighing the test pieces to an accuracy of at least1/5000. The balance shall have a capacity of at least5kg and a sensitivity of0,1

26、g. Its weighing pan (or weighing table) shall be wide enough to accommodate the test pieces so that they do not protrude outside the rim of the pan. NOTE 1As the test pieces are weighed when still hot, they cause an upstream flow of air around the weighing pan and, in consequence, a negative error i

27、n the balance reading. This error is minimized if the pan is wide enough So that no part of the test pieces protrudes outside the rim of the pan. 5.3 Equipment, for cutting the disc-shaped test pieces, comprising a commercial drill of about1kW, a drill stand, and a cutting tool. (SeeFigure 1 andFigu

28、re 2.) 5.4 Series of35cards, showing the complete sequence of sampling positions in each lap or wad from which the discs are to be cut. (See clause7 andFigure 3 andFigure 4.) One sample is taken from every wad, in the position indicated by the sampling cards, which have one corner clipped to ensure

29、correct orientation. Thirty-five cards are prepared and one sampling position is marked on each, so that each card represents the surface of one slab. A card size of100mm 75mm is suitable. The cards are divided into seven strips of equal width in one direction, and five in the other, thus giving35sa

30、mpling positions over the whole surface of the lap. 5.5 Equipment, for storing the test pieces to prevent them from gaining or losing mass before weighing. 5.6 Drying oven, with good ventilation, and capable of being controlled at105 C 2 C. 5.7 Drying containers, fitted with wire mesh. Outer rotatin

31、g part, consisting of a cone, an outer casing with four arms holding two cutting knives, and two chip breakers. Inner stationary part, consisting of a circular footplate, and an inner casing with spring holder and ball bearing. Coil spring, which expands between the rotating and the stationary parts

32、. Figure 1 Cutting tool (see5.3)BS4747-2:1995 BSI 11-1999 3 Figure 2 Cutting tool in useBS4747-2:1995 4 BSI 11-1999 Figure 3 The random card system (see5.4)BS4747-2:1995 BSI 11-1999 5 Figure 4 Sample selection by the random card systemBS4747-2:1995 6 BSI 11-1999 6 Sample bales For instructions conce

33、rning sample bales and sampling, see ISO801-1. The number of sample bales is specified inTable1 of ISO801-1; however, the total number of slabs in the bales taken shall be as close as possible to a whole multiple of35. The application of this principle to the most common cases (4,5 or6 slabs per bal

34、e) is illustrated in Table 1 of this part of ISO801. Table 1 Number of sample bales to be taken 7 Procedure 7.1 Weighing of sample bales Determine the gross mass of each sample bale separately and record it to an accuracy between1/500 and1/1000. If the moisture content of the wrappers obviously diff

35、ers from that of the rest of the bale, or if the wrappers are invoiced separately, test them separately in accordance with8.2. 7.2 Selection of specimen slabs or wads Sample every slab or wad in the table. 7.3 Cutting the test pieces SeeFigure 1 andFigure 2. From each slab or wad of pulp comprising

36、the complete base, cut a disc-shaped test piece, of diameter100mm2mm, with the cutting tool (see5.3 andFigure 1 andFigure 2) or a suitable modification of it. The test pieces when detached shall be of equal thickness, approximately20mm. Place the test pieces in the storing equipment (5.5) to prevent

37、 gain or loss of moisture, until the desired quantity has been accumulated for weighing as a batch. The positions of the discs to be taken from each slab are those indicated by the random card system (5.4). Drill each slab once only and collect the drillings in batches preferably containing samples

38、from each individual bale. The discs taken from the peripheral positions shall be taken at a distance of5mm to10mm from the edges of the slab. 7.4 Sampling using the random card system SeeFigure 3 andFigure 4. Shuffle the 35 cards and then take the first sample from the top slab at the position show

39、n on the top card. Sample the second slab in a similar way at the position indicated on the second card. Continue this procedure through each slab of the bales to be sampled until35 positions have been sampled. Reshuffle the pack of cards, and take the next sample as indicated by the top card. Use t

40、his procedure continuously, irrespective of the number of slabs contained in the bale. NOTE 2Accurate judgement of the sampling position can be made by reference to the marked sample card. However, if desired, a procedure which will assist the operator is to construct a lattice of the same dimension

41、s as the slabs in the bale, and with the same number of squares as that shown on the cards. The lattice is then placed on the surface of the slab to be drilled, and the disc can be cut while it is still in position. 7.5 Weighing and drying of the test pieces Collect the test pieces obtained, prefera

42、bly in batches containing those from a group of sample bales combined in such a way that the number of slabs tested is as close as possible to a multiple of35. Weigh to an accuracy of at least1/5000. NOTE 3It is essential that test pieces be prevented from losing or gaining mass before weighing. Ens

43、ure that the wire mesh at the bottom of the individual drying container (5.7) is sufficiently fine to retain small pieces of pulp, which can break away from some friable dry pulps, such as flash-dried groundwood. Dry the test pieces in the ventilated oven (5.6), controlled at105 C 2 C, until the mas

44、s is constant. This mass is considered to have been reached when two consecutive weighings, at an interval of at least1h, do not differ by more than1/5000. Total number of bales in lot Number of sample bales for 4 slabs/bale 5 slabs/bale 6 slabs/bale min. max. min. max. min. max. Up to 100 18 36 14

45、28 12 24 101 to 200 27 54 21 42 18 36 201 to 300 36 72 28 56 24 46 301 to 400 36 72 28 56 24 48 401 to 500 36 72 28 56 24 48 501 to 600 45 90 35 70 30 60 601 to 700 45 90 35 70 30 60 701 to 800 54 108 42 84 36 72 801 to 900 54 106 42 84 36 72 901 to 1000 63 126 49 98 42 84 1001 to 2000 72 144 56 112

46、 48 96 2001 to 3000 90 180 70 140 60 120 3001 to 4000 108 216 84 168 72 144 4001 to 5000 144 288 112 224 96 192 NOTEAbove5000, the minimum or maximum number is that given for5000 bales, plus1% of the bales in excess of5000. The total number of slabs taken shall be as close as possible to a multiple

47、of35.BS4747-2:1995 BSI 11-1999 7 Weigh the test pieces on the balance (5.2) immediately after their removal from the oven. The time interval from removal to weighing shall be less than30s. NOTE 4A prolonged time period between removal and weighing may cause a positive error in the oven dry mass, due

48、 to uptake of moisture from the ambient atmosphere. 8 Expression of results 8.1 Bales without wrappers and without specification The saleable mass X (at c %) of pulp in the lot is given, n kilograms, by the equation where Express the result to the nearest 1 kg. 8.2 Bales wrapped in pulp or paper she

49、ets When pulp is wrapped in wrappers consisting of pulp or paper sheets which have a moisture content which obviously differs from that of the remainder of the bale, or if wrappers are sold separately, the whole bale shall be weighed intact, and the wrapper or wrappers removed and weighed separately (the wrappers comprise all the pulp or paper sheets folded over the sides of the bales, and the sheets outside these). The gross mass of the wrappers, including wires or strappings, is then deducted from the gross m