1、 STD*BSI BS EN IS0 15755-ENGL 2000 3b24bb9 0873302 05b E BRITISH STANDARD Paper and board - Estimation of contraries The European Standard EN IS0 157551999 has the status of a British Standard ICs 85.060 IS EN IS0 .5755:2000 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMilTED BY COPYBIGET LAW STD-
2、BSI BS EN IS0 L5755-ENGL 2000 W 1624669 0873303 Tq2 been prepared under the direction of the Sector Committee for Materiais and Chemicals, was published under the authoris of the Standards Committee and comes into effect on 15June2000 Amd. No. O BSI 06-2000 ISBN O 580 34223 9 BS EN IS0 15755:2000 -
3、Date Comments - National foreword This British Standard is the official English language version of EN IS0 15755:1999. It is identical with IS0 157551999. The UK participation in its preparation was entrusted to Technical Committee PAV11, Test methods for paper, board and pulps, which has the respon
4、sibility to: - aid enquirers to understand the text; - present to the responsible internationalEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; them in the UK - monitor related international and European developments and promulgate
5、A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which hts normative references to international publications with their corresponding European p
6、ublications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electroni
7、c Catalogue. 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. Summary of pages ThLs docume
8、nt comprises a front cover, an inside front cover, the EN IS0 title page, pages 2 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. iB - STD-BSI BS EN IS0 15755-ENGL 2000 = 3b24bb9 O73104 929 m EUROPEAN STAN
9、DARD NORME EUROPENNE EUROPISCHE NORM EN IS0 15755 June 1999 ICs 85.060 English version Paper and board - Estimation of contraries (IS0 15755:1999) Papiers et cartons - Estimation des dbfauts (IS0 1 5755: 1 999) Papier und Pappe - Schtzung von Verunreinigungen (IS0 15755:1999) WS European Standard wa
10、s approved by GEN on 1 Apd 1999. CEN members are bound to comply with the CEWCENELEC Internal Regulations which stipulate the condidions for gMng hts European Standard the status ol a nabional standard without any elteration. Up-to-date lists and bibliographicel references concerning such national s
11、tandards may be obtained on application to the Central Secretariat or to MY CEN member. This European Standard exists in three official versions (English. French, German). A verdon in any other language made by translaon under the responJlbinty of a CEN member into its own language and notified to t
12、he Cemtrai Secretariat has the same status as the odal VeldonS. CEN members are the national standards bodies of Austria, Belgium. Czech Republic, Denmark. Finland, France, Germany, Greece, Iceland. Ireland, Ialy, Luxembourg, Netherlands, Norway. Portugal, Spain, Sweden, Switzerland and United Kingd
13、om. EUROPEAN COMMITTEE POR STANDARDiZATiON EUROPAISCHES KOMITEE FUR NORMUNG COMITI? EUROPBEN DE NORMALISATION Central Secretariat: rue de Stassart, 36 8-1050 Brussels Q 1999 CEN Ali rights of exploitation in MY form and by any means resewed worklwide for GEN national Members. Ref. No. EN IS0 15755:1
14、999 E STD.BSI BS EN IS0 L5755-ENGL 2000 1b24bh 0073105 865 m Page 2 EN IS0 15755:1999 1 2 3 4 5 6 7 0 9 Annex A Annex B Annex C Content Page Foreword 3 Scope . 4 Normative References . 4 Principle 4 Preparation of sample . 5 Procedure 5 Expression of results 6 Introduction 4 Definitions 4 Apparatus
15、4 Test report 6 (normative)Compansonchari 7 (normative) Instrumental procedure 8 (informative) Bibliography 1 O STD-BSI BS EN IS0 15755-ENGL 2000 W 1b24bb9 0873306 7Tl Page 3 EN IS0 15755:1999 Fomword The text of EN IS0 15755:1999 has been prepared by Technical Committee CEWC 172 Pulp, paper and boa
16、rd, the secretariat of whlch is held by DIN, in collaboration with Technical Committee ISO/TC 6 Paper, board and Pulps- This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 1999, and conflicin
17、g national standards shall be withdrawn at the latest by December 1999. According to aie CEWCENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium. Czech Republic, Denmark, Finland, France, Germany
18、, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Swizerland and the United Klngdom. STD-BSI BS EN IS0 15755-ENGL 2000 W 3ib24bb7 0873l107 b3 m Page 4 EN IS0 15755:1999 Introduction This European Standard is based on a visual inspection, and a normative Ann
19、ex B is added where the inspection is perfamed using instrumental devices. This is justified by the present state of instrument development. For the time being, the visual procedure is the foremost European Standard. This can eventually be changed when more experience with instrumental devices is ga
20、ined and it has been shown that such equipment can estimate contraries to a level of precision at least equal to visual inspection. Estimation of dirt and shives by a visual technique is a well established method in the pulp and paper industry and the estimation of these contraries is important for
21、trade purposes. 1 Scope This European Standard specifies the test method for the estimation by reflected light of the visible contraries in paper. Visual inspection is applicable to most kinds of paper and board. Paper and board with an apparently high conteint of contraries require to be inspected
22、by instrumental means as described in Annex B, as the tedium of large counts diminishes the judges precision. However, papers which are not flat, have a low lightness (Y value below 30 %) and contain holes may cause particular problems for instrumental techniques (see Annex 8). Fluorescent spots wil
23、l not be detected by the methods described in this European Standard. 2 Normative References This European Standard incorporates by datecl or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are lis
24、ted hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN IS0 186 Paper and board
25、- Sampling to determine average quality (IS0 186 : 1994) 3 Definitions For the purposes of this Standard, the following definitions apply: 3.1 sheet: a sheet of paper or board taken from a packet, bale or roll of paper. 32 test piece: an area recognized for inspection. 3.3 contrary (in paper or boar
26、d): any unwanted particle or spot of specified minimum size and having a sufficiently contrasting light reflectance with respect to the surrounding area of the sheet, according to the comparison chart in Annex A (see figure A.1). NOTE: A contrary can include any blemish on the paper surface. 4 Princ
27、iple The test pieces to be examined have to be inspected in reflected light, The area of each contrary larger than a specified value and showing contrasting light reflectance with respect to the surrounding area of the sheet, according to !he comparison chart presented in Annex A has to be estimated
28、. The areas of the contraries are added and the total area of contraries is reported as square miIlimetfie per square meter of paper (mm2/m2). If required, the areas of Contraries in different classes can also be reported. 5 Apparatus 5.1 Iliumhation device: a suitable light source for investigation
29、 of the paper in reflected light. The light shall be strong enough to ensure that all contraries having the minimum area agreed upon (see subclause 7.2) are visible. Natural daylight or direct light from any extemal source shall be avoided. 5.2 Comparison chart: a film with a cenes of black and grey
30、 spots of different shapes, areas and contrasts. This shall be used for visual inspection and for checking the performance of an instrument. The chart is included in Annex A of this European Standard. Do nd use the illustration in Annex A, or any copy thereof in any inspection, because reproduction
31、can change the size and the contrast of !he spots. STD-BSI BS EN IS0 15755-ENGL 2000 3624669 0873108 57Y II Size Area Logarithmic mean area class mW mW 1 above 5 2 1,oo to 4,9Q 2,234 3 0,40 to 0,99 0,629 4 0,15 to 0,39 0,242 5 0,04 to 0,14 0,075 - 6 0,Ol to 0,03 0,017 Page 5 EN IS0 157551 999 6 Prep
32、aration of sample 6.1 Sampling if the dirt count is to represent the contraries in a lot of paper, the number of samples to be inspected and the method of selecting them shall be in accordance with EN IS0 186. For minimum size of sample see 6.2. 6.2 Selection of areas for inspection Idem a number of
33、 areas (test pieces) randomly distributed over the different parts and equally representing both sides of the samptes. The total area to be inspected is such, as to allow for the counting of at least 300 contraries. However, if very few contraries can be found, as in a very clean paper, the area to
34、be inspected need not exceed 3 I#. However, the judgement on a tot of paper or board shall be based on not less than loo0 contraries or 10 m2 of paper or board. NOTE 1: The above number of contraries are anived at by accepting a relative error of 10% at a confidence level of 9OOA l. NOTE 2: The cont
35、raries are likely to be unevenly distributed in the paper and the result can vary considerably depending on how the test areas are selected. It is important that these areas are randomly distributed over the whole sample if this is larger than the minimum size indicated above. NOTE 3: In some cases
36、only one side of the sample is inspected. This should be stated in the test report. 7 Procedure 7.1 Examination Examine the test pieces (6.2) visually to determine the area of the contraries. Use the comparison chart in Annex A. Nomially, only contraries having an area of at least 0.04 mm2 shall be
37、noted. Classify .the contraries according to their area (see table 1). Do not count any atypical, non-representative piece of dirt, such as a crushed insect or a blotch of dirt, but report it together with the result. Do not count fluorescent spots. NOTE: On request, the size of contraries of differ
38、ent types can be noted separately, as for example plastics, dirt, shives etc. 7.2 Classification of contraries It is usual to report only the total area, though when required the contrary area in each class can be reported. In this case the classification given in table 1 shall be used. Size class 6
39、 is used only by special agreement and this shall be stated in the test report. Table 1 : Recommended classlflcatlon of contraries accordlng to area NOTE: The number of classes used can be varied to some degree depending on the grade of paper or board tested and agreement between the parties concern
40、ed. Page 6 EN IS0 15755: 1 999 8 Expression of results 8.1 Calculation For all contraries calculate the total area, or the area in each size class (see table l), according to the formula: ci “i X=X- b where X q q b For contraries exceeding 5 mm2 q must be replaced by the contraries true area, which
41、shall be evaluated separately for each contrary and stated in the test report. NOTE: The logarithmic mean area of a class is justified, as there is a tendency towards enrichment of contraries towards the lower limit of the class. is the total area of contraries (or of the Contraries in each size cla
42、ss per area of paper), expressed in square millimetres per square meter; is the logarithmic mean area of each class, as reported in table 1, expressed in square millimetres; is the number of contraries in the class; is the area of the inspected sample, expressed in square metres. EXAMPLE If 8 contra
43、ries are counted within the size class 0,15 to 0,39, their area c, . 4 is calculated as follows: 8 x 0,242 mmz = 1,9 mm2 (see table 1). 8.2 Results Report the total area of contraries per area of paper to the nearest integer. Results below 5 mmYW shall be reported to one decimal place. NOTE: On requ
44、est, the result can be expressed separately for each size class. However, categories containing few contraries will be subject to much higher sampling uncertainty. 8.3 Precision It is difficult to obtain exact precision data for a visual dirt count because of the subjective nature of the test method
45、. i! is an established fact that the reproducibility is unsatisfactory because of differences in personal judgement. Five laboratories tested 16 paper samples visually. The coefficient of variation between the laboratories was found to vaiy from 62 % to 99 %, the mean value being 02 Yo. 9 Testreport
46、 The test report shall refer to this European Standard and state: a) ail information necessary for complete identification of the sample or lot; b) the result expressed in square millimetres per square metre of paper or board. On request, the result can be divided into classes according to size or t
47、ype; c) the area of paper inspected in square metres; d) whether the result is based on a visual or an instrumental inspection; e) any optional points observed in the course of the test; 9 any departure from this European Standard, or any circumstances regarded as optional that may haveaffected the
48、result. STD-BSI BS EN IS0 15755-ENGL 2000 1624669 0873110 122 I Page 7 EN IS0 157551999 Annex A (normative) Comparison chart Use the chart here enclosed. Contrast (%I Contraste (%) 30 50 80 100 DBB Q O Aspect ratio Facteur de forme 2 5 20 Area Surface mm2 5.00 1 .o0 0.40 0.15 0.04 0.01 Scale I 0,15
49、mm2 and 0.04 mW. The spots on the right hand indicate contraries of different aspect ratios. The contrast ratio is 100 %. This part of the chart is to be used as an aid for size classification. STD*BSI BS EN IS0 25755-ENGL 2000 I 2624669 0873LLL Ob7 Page 8 EN IC0 15755:1999 Annex B (normative) Instrumental procedure B.1 Introduction Instruments are commonly used for inspection of contraries in paper. Such techniques are preferably used for paperc with a high number of contraries. However, it should be noted that results obtained by visual inspection may not be eq
