1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ICS 83.060 ISBN 0-626-14426-4 SANS 11345:2003 Edition 1 ISO 11345:1997 Edition 1 SOUTH AFRICAN NATIONAL STANDARD Rubber Assessment of carbon black disper
4、sion Rapid comparative methods Published by Standards South Africa 1 dr lategan road groenkloof ! private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa 2003 This national standard is the identical implementation of ISO 1
5、1345:1997 and is adopted with the permission of the International Organization for Standardization SANS 11345:2003 Edition 1 ISO 11345:1997 Edition 1 Table of changes Change No. Date Scope National Foreword This South African standard was approved by National Committee STANSA TC 5140.17, Rubber and
6、rubber products, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. INTERNATIONAL STANDARD IS0 11345 First edition 1997-l 2-15 Rubber - Assessment of carbon black dispersion - Rapid comparative methods Caoutchouc - a=400net; p=iso; o=isocs;
7、s=central Printed in Switzerland ii IS0 11345:1997(E) Introduction The degree of carbon black dispersion in a rubber compound is important because certain physical properties, e.g. tensile strength, hysteresis and abrasion resistance, are influenced by dispersion. This method makes use of the well k
8、nown fact that in a compound in which the ingredients are well dispersed, light is reflected from a freshly cut surface revealing a smooth, unblemished texture. The presence of improperly dispersed ingredients is shown by irregularities which usually take the form of circular, convex “bumps” or conc
9、ave pockmarks on the surface, and their presence indicates a less-than- perfect dispersion of the compounding ingredients. The size and frequency of these irregularities may be used to judge the degree to which the compound falls short of an optimum dispersion. A set of ten standards based on size a
10、nd frequency of these irregularities has been established to which numerical ratings have been assigned. This scherme provides a means of evaluating dispersion in a rubber compound and assigns numerical designations to the degrees of dispersion. This International Standard describes test procedures
11、for assessing the degree of macrodispersion of carbon black in rubber. The methods are primarily intended to be used as rapid factory controls during mixing and subsequent processing stages to assure adequate carbon black dispersion. Two test methods are described: Method A: Visual microscopic or ph
12、otographic/microscopic inspection Method B: Split-field microscopic inspection . . . III This page intentionally left blank - INTERNATIONAL STANDARD IS0 IS0 11345:1997(E) Rubber - Assessment of carbon black dispersion - Rapid comparative methods WARNING - Persons using this International Standard sh
13、all be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory cond
14、itions. 1 Scope This International Standard specifies qualitative visual test methods for the rapid and comparative assessment of macrodispersion only of carbon black in rubber. Ratings are made reiative to a set of standard photographs (ratings 1 - IO), and the results are expressed on a numerical
15、scale. This International Standard, with its standard photographs, is applicable only to compounds which contain carbon black. 2 Principle The carbon black filled rubber compound is cut to expose a fresh surface for examination at a magnification of 30 x. Two alternative methods are described: Metho
16、d A: Visual microscopic or photographic/microscopic inspection Method 8: Split-fieid microscopic inspection The dispersion level of the carbon black is compared with a series of ten photographic or electronically stored standards photographed with oblique illumination of 30 at an effective magnifica
17、tion of 30 x and then rated numerically from IO (excellent) to 1 (very poor). (Figure 1). A rating of IO indicates a state of dispersion having near maximum physical propemes while a rating of 1 would indicate structural flaws causing consider-ably decreased physical propetiies. NormaIIy, the visual
18、 dispersion ratings indicate the foliowing levels of compound quality. e Visual dispersion Dispersion rating classification 9-10 excellent 8 good 7 acceptable 5-6 doubt,ful 3-4 poor l-2 very poor IS0 11345:1997(E) 3 Method A - Visual microscopic or photographic/microscopic inspection 3.1 Apparatus 3
19、.1.1 IRazor blade - single edge, attached to a sample cutter. 3.1.2 Sample cutter comprising a lever mechanism which provides a vertical cutting action and a razor blade holder. 3.1.3 Binocular microscope (30 x), or 3.1.4 Binocular microscope (30 x) equipped with a standard self developing (Polaroid
20、 type) camera. 3.1.5 Illuminator, microscopical-type, with high luminous intensity. 3.2 Test piece 3.2.1 Vulcanized compound Cut a test piece, using the sample cutter, with a cross section of approximately 5 x 8 mm. Do not touch the surface to be used for rating. The razor blade shall be replaced be
21、fore the edge wears such that the cut becomes lined. For cured compounds the razor blade should be at standard laboratory temperature. 3.2.2 Unvulcanized compound The compound shall first be compressed to remove most of the air holes since, even in small amounts, they can have the appearance of poor
22、ly dispersed carbon black and can therefore affect the rating. To accomplish this, press the rubber into a slab between thin sheets of plastic in a mould at a pressure of about I kPa for 5 min at 105 “C. Care should be taken to avoid excessive flow during this step. The surface to be examined should
23、, as far as possible, be free from distortion and blemishes. To achieve this the cutting edge of the tool should be free from defects and the distortion of the sample shall be minimized by applying the cutting pressure evenly and slowly, with a sharp razor blade, heated to approximately 100 “C. Howe
24、ver, even with all these precautions the evaluation of a cured specimen of the same compound may give a different result. 3.3 Procedure Examine the prepared test piece under the binocular microscope with oblique illumination (at an angle of incidence 30) to accentuate surface detail. The illuminator
25、 shall preferentially be placed parallel to the direction of cutting since any cutting lines will show less. Compare the size and frequency of carbon black agglomerates in the specimens (showing up as surface bumps or depressions) to the standard photographs. NOTE 1 - If a microscope with a self dev
26、eloping camera is used, the dispersion can be rated through a side by side comparison with the standard photographs using the photograph obtained. This provides a permanent record of the test piece appearance in a matter of minutes. Assign the most closely matched numerical rating to each compound b
27、eing rated in whole numbers. For closer matching use fractional ratings; 5 l/2 would indicate a rating between 5 and 6. A rating of IO indicates a state of dispersion having near maximum physical properties while a rating of I would indicate structural flaws causing decreased physical properties. IS
28、0 IS0 11345:1997(E) 4 Method B - Split-field microscopic inspection Method B is a test method which determines the degree of dispersion of carbon black in rubber compounds by means of a split-field video camera arrangement, which is used to rate the test piece against a set of transparencies or elec
29、tronically stored standard references. The assessment of carbon black dispersion using the split-field optical microscopic technique is accomplished by a co-projection of the standard references images and the test piece image on a video-monitor using a black and white video camera. The references a
30、re identical to the photographic standards referred to in Method A. 4.1 Apparatus 4.1.1 Razor blade, see 3.1.1. 4.1.2 Sample cutter, see 3.1.2. 4.1.3 Equipment for split-field representation. The instrument is based on the so-called split-field optical microscopic technique where the photographic IO
31、-grade standard is projected side by side with the reflected image of the test piece surface. The reference pictures are mounted on a rotary disc or are electronically stored and can be operated so that the reference standard matches the appearance of the test piece surface. A video or a CCD camera
32、could be used together with a monitor to provide a side by side composite picture of test piece and standard. (Figures 2a and 2b). 4.2 Test piece The test pieces needed for Method B shall be prepared in the same manner as described in 3.2. 4.3 Procedure Activate the instrument and allow for the spec
33、ified warm-up time. Place the test piece with the fresh cut surface against the test piece holder. The test piece shall be placed the same way as in the cutter, with the cutting direction vertical. Examine the prepared test piece in the instrument with oblique illumination (at an angle of incidence
34、30”). Compare the size and frequency of carbon black agglomerates in the test piece (showing up as bumps or depressions) to the standard photographs by direct side by side comparison. Chose amongst the stored standard reference pictures, the standard photography that closest matches the image of the
35、 test piece by systematically switching the reference pictures in the side position to the image under examination. Assign the most closely matched numerical rating to each compound being rated in whole numbers. For closer matching use fractional ratings; 5 l/2 would indicate a rating between 5 and
36、6. A rating of IO indicates a state of dispersion having near maximum physical properties while a rating of 1 would indicate structural flaws causing decreased physical properties. 5 Number of tests Preferably more than one test on different parts of each test specimen should be taken. 3 IS0 11345:
37、1997(E) 6 Test report The test report shall include the following information: a) a reference to this International Standard; b) a complete identificatio Inoft he m aterial tested, including type, source, manufacturers code num ber and previous history; c) whether Method A or B was used; d) list the
38、 rating on the basis of the 10 to 1 scale by the photographic standards. Use fractional ratings when necessary. If more than one operator has rated the material, the number of observations and the average rating should be reported; whether vulcanized or unvulcanized, e) the date of test. IS0 IS0 113
39、45:1997(E) T31 c .- cr3 a 00 03 c .- m a m c .- cc1 a 0 I m c .- a a Figure 1 - Photc sgraptiic standards CT) c .- m a m c .- m a m m c .- c13 a CTI c .- co a m c .- cr3 a 5 IS0 11345:1997(E) IS0 2 3 9 4 5 2 6 I t A: c / - 5 10 c Key 1 Light 6 Reference 2 Lamp 7 Test piece holder 3 Video camera 8 Pr
40、ism 4 Video monitor 9 Reference tranwarencv 5 Test piece 10 Transparency carrier a) With video camera Figure 2 - Apparatus for method B IS0 IS0 11345: 1997(E) 2 r Key 1 Lamp 2 CCD camera 3 Electronics 4 Microcomputer 5 Test piece 6 4 3 I . 10 000000000000 000000000000 6 Reference 7 Digital memory (r
41、eference pictures) 8 Light 9 Test piece holder IO Keyboard lb) With CCD camera Figure 2 - Apparatus for method B (concluded) 7 IS0 11345:1997(E) Annex A (informative) Photographic standards and test equipment Photographic s obtained from tandards, electronically stored or on paper, and the equipment specified for method B may be Optigrade AB Box 733 S-931 27 Skelleftei Sweden Telephone +4691083530 Telefax +4691039880
