1、 Reference number ISO 22498:2005(E) ISO 2005INTERNATIONAL STANDARD ISO 22498 First edition 2005-07-15 Plastics Vinyl chloride homopolymer and copolymer resins Particle size determination by mechanical sieving Plastiques Rsines dhomopolymres et de copolymres de chlorure de vinyle Dtermination de la t
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5、rm the Central Secretariat at the address given below. ISO 2005 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from e
6、ither ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedISO 22498:2005(E) IS
7、O 2005 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Principle. 2 5 Materials 2 6 Apparatus 2 7 Procedure 2 8 Number of determinations . 3 9 Calculation and expression of results 3 10 Precision 4 11 Test report . 4 ISO 22498:200
8、5(E) iv ISO 2005 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body i
9、nterested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechn
10、ical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by th
11、e technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights
12、. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22498 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic materials. INTERNATIONAL STANDARD ISO 22498:2005(E) ISO 2005 All rights reserved 1 Plastics Vinyl chloride homopolyme
13、r and copolymer resins Particle size determination by mechanical sieving 1 Scope This International Standard specifies a method for the determination of the size distribution of particles of vinyl chloride homopolymer and copolymer resins by measuring the amounts retained on a selection of sieves ha
14、ving meshes of various aperture sizes. The results can be expressed either in terms of the amount retained on the individual sieves or as the mean particle size for the whole test sample. The method is not recommended for use with sieves having mesh sizes smaller than 0,038 mm. 2 Normative reference
15、s The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 565, Test sieves Metal wire cloth, perforat
16、ed metal plate and electroformed sheet Nominal sizes of openings ISO 868, Plastics and ebonite Determination of indentation hardness by means of a durometer (Shore hardness) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 sieve retention perc
17、entage, by mass, of the resin test sample retained on a given sieve at the end of the test procedure 3.2 pan retention percentage, by mass, of the resin test sample retained in the pan at the bottom of the stack of sieves, or under a single sieve, at the end of the test procedure 3.3 mean particle s
18、ize single value, expressed to the nearest 0,001 mm, representing the dominant particle of the whole test sample ISO 22498:2005(E) 2 ISO 2005 All rights reserved4 Principle A test sample of resin is sieved through a single sieve, or through a stack of sieves of various mesh sizes, assisted by mechan
19、ical shaking. When several sieves are chosen to form a stack, the sieves are assembled in ascending order of mesh size so that the largest mesh size is at the top. 5 Materials 5.1 Antistatic agent: aluminium oxide powder, carbon black or equivalent. 5.2 Blocks of non-sticking rubber, with a Shore A
20、hardness typically between 70 and 80, and with dimensions of approximately 40 mm 10 mm 15 mm. 6 Apparatus 6.1 Balance, accurate to 0,001 g. 6.2 Balance, accurate to 0,1 g, range and size sufficient to accommodate the individual sieves and the resin retained on them. 6.3 Sieves, nominally 200 mm in d
21、iameter, conforming to ISO 565, complete with lid and base pan receiver. It is recommended that sieves with mesh sizes of 0,425 mm, 0,250 mm, 0,150 mm, 0,106 mm, 0,075 mm and 0,063 mm are available as a minimum. In cases of dispute, the sieve mesh sizes to be used shall be agreed between the interes
22、ted parties. 6.4 Sieve shaker: a mechanical device preferably fitted with an automatic time switch. The device shall be capable of subjecting the sieve, or stack of sieves, to a uniform vertical motion that is completed by a “tap” or “jerk” at the end of each stroke. The “tapping rate” shall be 150
23、15 taps per minute. 6.5 Soft-bristle brush. 6.6 Vacuum cleaner, suitable for and electrically safe with very fine powders. 7 Procedure 7.1 Ensure that the sieve or sieves, the lid and the pan are free from resin particles by cleaning with the vacuum cleaner (6.6), releasing any stubborn remains by g
24、entle use of the brush (6.5). 7.2 Examine the sieve or sieves for damage to the mesh or distortion of the mesh matrix. Replace any sieve found to show these defects. 7.3 Weigh the sieve, or each individual sieve, to the nearest 0,1 g. 7.4 Weigh the pan to the nearest 0,1 g. 7.5 Assemble the sieve or
25、 sieves and the pan, one on top of the other, adding two or three blocks of rubber (5.2) to each sieve. When assembling a stack of sieves, ensure that they are assembled in ascending order of mesh size so that the sieve with the largest apertures is at the top. When using a stack of sieves to determ
26、ine mean particle size (see 9.3), it is necessary to choose a selection of mesh aperture sizes such that the combined retentions on the top sieve and pan are 4,0 % of the test sample. As many sieves as practical shall be used having a graded distribution of mesh sizes. A possible combination of siev
27、es is given in 6.3. ISO 22498:2005(E) ISO 2005 All rights reserved 3 7.6 Weigh out 20,0 g 0,1 g of the resin sample and add anti-static agent (5.1). The amount of anti-static agent used shall be just sufficient to facilitate the easy movement of the powder but in no case shall it be more than 0,1 %
28、of the mass of the test sample. 7.7 Mix the weighed test sample and the anti-static agent with a spatula and transfer the mixture to the top sieve, avoiding spillage or the fomation of a dust cloud. Use the brush to complete the transfer if necessary. 7.8 Cover the sieve or stack of sieves with the
29、lid and clamp into the mechanical sieve shaker. 7.9 Set the timer on the shaker for 13 min 2 min and switch on. 7.10 After shaking, carefully separate the sieve or sieves, beginning at the top. Carefully remove the rubber blocks, returning any adhering powder to the sieve concerned. Weigh the sieve,
30、 or each sieve, and the pan together with their contents. 8 Number of determinations Make two determinations for each sample tested. 9 Calculation and expression of results 9.1 Calculation of the average mass of resin retained on each sieve and in the pan For each sieve and for the pan, calculate th
31、e mass, in grams, of resin retained in the first determination Equation (1) and in the second determination Equation (2): m 1 m 2= m 3(1) m 4 m 5= m 6(2) where m 1and m 4are the masses, in the first and second determinations, respectively, of the sieve or pan plus retained resin; m 2and m 5are the m
32、asses, in the first and second determinations, respectively, of the sieve or pan alone; m 3and m 6are the masses, in the first and second determinations, respectively, of resin retained by the sieve or pan; Then calculate, for each sieve and for the pan, the average mass m r , in grams, of resin ret
33、ained, i.e. the average of the two determinations, as follows: 36 r 2 mm m + = (3) 9.2 Calculation of the percentage of the test sample retained on each sieve and in the pan For each sieve and for the pan, calculate the percentage R of the test sample retained, as follows: r s 100 m R m = (4) where
34、m sis the average mass, in grams, of the two test samples taken. ISO 22498:2005(E) 4 ISO 2005 All rights reserved9.3 Calculation of mean particle size 9.3.1 Calculate the percentage R of the test sample retained by each sieve and the pan in accordance with 9.1 and 9.2. The cumulative total of the va
35、lues for the whole stack of sieves, together with the pan, shall amount to 99 %. If this is not the case, the test procedure shall be repeated. 9.3.2 Starting from the top of the stack of sieves, divide the stack into adjacent pairs and calculate the mean size of the resin particles retained on the
36、lower sieve in each pair (that with the smaller mesh size) as follows: 12 2 dd D + = (5) where D is the average size, in mm, of the resin particles retained on the sieve with the smaller mesh size; d 1is the mesh size, in mm, of the sieve with the larger mesh size; d 2is the mesh size, in mm, of the
37、 sieve with the smaller mesh size. 9.3.3 Calculate the mean particle size for the test sample as follows: Mean particle size = (D 1 R 1 ) + (D 2 R 2 ) + + (D n R n ) (6) where D 1 , D 2 , . D nare the average particle sizes, in mm, for each of the pairs of sieves forming the stack, calculated using
38、Equation (5); R 1 , R 2 , . R nare the percentages of resin retained on the sieve with the smaller mesh aperture in each pair. For the purposes of the calculation of the mean particle size, the resin retained on the sieve with the biggest mesh size and in the pan shall be ignored. 10 Precision The p
39、recision of this method is not known as interlaboratory data are not available. 11 Test report The test report shall contain the following particulars: a) a reference to this International Standard; b) all details necessary to identify the resin tested; c) the anti-static agent used; d) the values o
40、f the properties determined, i.e. the percentage of the test sample retained on the sieves of various mesh sizes and/or the mean particle size for the whole test sample; e) the date of the test. ISO 22498:2005(E) ISO 2005 All rights reserved 5Key 1 wire cloth sieve Figure 1 Typical mechanical sieve-shaking device ISO 22498:2005(E) ICS 83.080.20 Price based on 5 pages ISO 2005 All rights reserved
