1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 1652:2011Rubber latex Determinationof apparent viscosity by theBrookfield test methodBS ISO 1652:2011 BRITISH STANDARDNational forewordThis British Standard is the UK impl
2、ementation of ISO 1652:2011. Itsupersedes BS ISO 1652:2004 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/50, Rubber - Raw, natural and synthetic, includinglatex and carbon black.A list of organizations represented on this committee can beobtained
3、on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 72981 2ICS 83.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This Britis
4、h Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2011.Amendments issued since publicationDate Text affectedBS ISO 1652:2011Reference numberISO 1652:2011(E)ISO 2011INTERNATIONAL STANDARD ISO1652Fourth edition2011-03-15Rubber latex Determination of
5、 apparent viscosity by the Brookfield test method Latex de caoutchouc Dtermination de la viscosit apparente par la mthode dessai de Brookfield BS ISO 1652:2011ISO 1652:2011(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be pr
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8、is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduc
9、ed or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either 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
10、01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 1652:2011ISO 1652:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle .1 5 Apparatu
11、s.2 6 Sampling 2 7 Further preparation of test sample4 8 Procedure.4 9 Expression of results5 10 Precision 5 11 Test report5 Annex A (informative) Viscosity-measurement methods .6 Annex B (informative) Precision statement7 Bibliography9 BS ISO 1652:2011ISO 1652:2011(E) iv ISO 2011 All rights reserve
12、dForeword 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 interested in a subject for which a
13、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 Electrotechnical Commission (IEC) on all matter
14、s 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 the technical committees are circulat
15、ed 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. ISO shall not be held responsible
16、 for identifying any or all such patent rights. ISO 1652 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 3, Raw materials (including latex) for use in the rubber industry. This fourth edition cancels and replaces the third edition (ISO 1652:2004), which has
17、 been technically revised. The main change is the inclusion of precision data (see Annex B). BS ISO 1652:2011INTERNATIONAL STANDARD ISO 1652:2011(E) ISO 2011 All rights reserved 1Rubber latex Determination of apparent viscosity by the Brookfield test method WARNING Persons using this International S
18、tandard should 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 regu
19、latory conditions. 1 Scope This International Standard specifies a method for the determination of the apparent viscosity of both natural rubber latex concentrate and synthetic rubber latices by the Brookfield method. The method is also suitable for the determination of the viscosity of natural lati
20、ces from sources other than Hevea brasiliensis and also for compounded latices. Other methods for the determination of viscosity are referred to in Annex A. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only th
21、e edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 123, Rubber latex Sampling ISO 124, Latex, rubber Determination of total solids content 3 Terms and definitions For the purposes of this document, the following term
22、s and definitions apply. 3.1 test sample quantity of latex suitable for testing, obtained by straining a laboratory sample ISO 123 4 Principle The viscosity of a latex sample is determined by means of a viscometer which measures the torque produced on a specific spindle driven by an electric motor t
23、o rotate at a constant rotational frequency and at a controlled rate of shear while immersed to a specified depth in the latex. The apparent viscosity is obtained by multiplying the torque reading by a coefficient which depends on the rotational frequency and size of the spindle. Measurements may be
24、 made on the undiluted latex or on the latex after dilution to a required total-solids content. This International Standard relates primarily to the manually operated type of viscometer rather than the digital ones currently produced. Comparative reference is made to the latter where appropriate. NO
25、TE Other methods exist for the determination of the viscosity of latices and emulsions (see Annex A). BS ISO 1652:2011ISO 1652:2011(E) 2 ISO 2011 All rights reserved5 Apparatus 5.1 Viscometer, consisting of an electric motor which drives, at a constant rotational frequency, a shaft to which spindles
26、 of different shapes and dimensions may be attached. The rotational frequency can be selected from a number of speeds. For the purpose of this International Standard, two are specified but other speeds may be used for practical reasons. The spindle is immersed in the latex to a specified depth and t
27、he drag on the spindle rotating in the latex causes a torque to be developed on the spindle shaft. The equilibrium torque developed is indicated by means of a pointer and a scale which is calibrated in units from 0 to 1001). The L instrument uses a spring torque of 67,37 Nm 0,07 Nm (673,7 dyncm 0,7
28、dyncm) at full-scale deflection. The R instrument uses a spring torque of 718,7 Nm 0,7 Nm (7 187 dyncm 7 dyncm) at full-scale deflection. The spindles shall be accurately made in accordance with Figure 1 and the dimensions given in Table 1. They shall have a groove, or other marking device, on the s
29、haft to indicate the required depth of immersion. A spirit level shall be incorporated in the motor housing to indicate, with the spindle attached to the motor shaft, when the spindle is vertical. A guard shall be used to protect the spindle in operation. This shall consist of a rectangular bar of c
30、ross-section approximately 9,5 mm 3 mm, with the corners rounded, bent into a U. The upper ends of the guard shall be attached to the motor housing in such a way that the guard is removable for cleaning. The horizontal portion of the guard shall join the vertical legs of the guard through internal r
31、adii of approximately 6 mm. NOTE Although the function of the guard is primarily for protection, it is an integral part of the equipment and the measured viscosity is likely to change if it is not in place. The perpendicular distance between the inner faces of the two vertical legs of the guard when
32、 the guard is securely attached to the motor housing shall be 31,8 mm 0,8 mm with the L instrument and 76,2 mm 0,8 mm with the R instrument. The perpendicular distance between the upper face of the horizontal portion of the guard and the bottom of the spindle shaft, when the guard is securely attach
33、ed to the motor housing and when the spindle is attached to the motor shaft, shall be not less than 10 mm with the L instrument and not less than 4,5 mm with the R instrument. 5.2 Beaker, glass, of internal diameter at least 85 mm and capacity 600 cm3. The actual value of the viscosity determined is
34、 affected by the size of the beaker. Care shall therefore be taken to ensure that the size of the container used is consistent. 5.3 Water-bath, capable of being maintained at 23 C 2 C, or 27 C 2 C in tropical climates. 6 Sampling Carry out sampling in accordance with one of the methods described in
35、ISO 123. From the sample thus obtained, prepare a test sample as specified in ISO 123. 1) Suitable instruments are obtainable from several sources, such as Brookfield Engineering Laboratories, Inc., Stoughton, Mass. 02072, USA (whose models LVF and LVT meet the requirements for the L instrument and
36、models RVF and RVT meet the requirements for the R instrument) and Gebrder Haake GmbH, Dieselstr. 4, D-76227 Karlsruhe, Germany. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of these products. BS ISO 1652:2011ISO
37、1652:2011(E) ISO 2011 All rights reserved 3a) No. L1 b) Nos. L2 and L3 c) No. R1 d) Nos. R2 and R3 Figure 1 Spindles BS ISO 1652:2011ISO 1652:2011(E) 4 ISO 2011 All rights reservedTable 1 Spindle dimensions Values in millimetres Spindle number A 1,3 B 0,03 C 0,03 D 0,06 E 1,3 F 0,15 L1 L2 L3 115,1 1
38、15,1 115,1 3,18 3,18 3,18 18,84 18,72 12,70 65,10 6,86 1,65 25,4 25,4 81,0 50,0 50,0 R1 R2 R3 133,3 133,3 133,3 3,18 3,18 3,18 56,26a46,93 34,69 22,48b1,57 1,65 27,0 27,0 27,0 61,1 49,2 49,2 aWall thickness approximately 0,6 mm. bWall thickness approximately 1,0 mm. 7 Further preparation of test sam
39、ple If the requirement is for the viscosity at a specific solids content, determine the total solids content of the test sample of latex in accordance with ISO 124 and then, if necessary, accurately adjust to the required value by the addition of distilled water or water of equivalent purity. Add th
40、e water slowly to the latex and stir the mixture gently for 5 min, taking care to avoid the inclusion of air. If the test sample contains occluded air and has a viscosity of less than 200 mPas (200 cP), remove the air by allowing the latex to stand for 24 h. If the latex contains occluded air and no
41、 other volatile component, and has a viscosity greater than about 200 mPas (200 cP), remove the air by allowing the latex to stand under vacuum until foaming ceases. 8 Procedure Pour a portion of the test sample (see Clause 7) into the beaker (5.2). Place the beaker in the water-bath (5.3), maintain
42、ed at 23 C 2 C or 27 C 2 C, and stir the latex gently until its temperature is 23 C 2 C or 27 C 2 C. Record the precise temperature. Immediately attach the spindle securely to the motor shaft and attach the guard securely to the motor housing of the viscometer (5.1). Carefully insert the spindle and
43、 guard into the latex, in such a way as to avoid air being trapped on the underside of the spindle, until the surface of the latex is at the midpoint of the groove on the spindle shaft. The spindle shall be positioned vertically in the sample (as indicated by the spirit level on the motor housing) a
44、nd in the centre of the beaker. Select the rotational frequency of the instrument as follows: L instrument: 60 min1 0,2 min1(1 s1 0,003 s1) R instrument: 20 min1 0,2 min1(0,333 s1 0,003 s1) Switch on the viscometer motor and take the equilibrium reading to the nearest unit scale division, in accorda
45、nce with the manufacturers operating instructions. Equilibrium may not be attained until 20 s to 30 s have elapsed. It is preferable to have a reading between 10 and 90 scale units. If the reading is less than 10 scale units or greater than 90 scale units, then a further reading should be taken usin
46、g the next larger or smaller spindle, respectively. This refinement is not practical with digital viscometers. If the method is being used for monitoring or quality control purposes, care shall be taken to ensure that the spindle size and rotational frequency are constant. BS ISO 1652:2011ISO 1652:2
47、011(E) ISO 2011 All rights reserved 5For specific purposes, such as the assessment of rheological characteristics, it may be desirable to measure the viscosity at more than one rotational frequency (see Annex A). For this purpose, the viscometer shall be switched off and the latex allowed to stand f
48、or not less than 30 s before restarting at another speed. If the determination is made at more than one rotational frequency or at speeds other than those specified above, this fact shall be included in the test report. 9 Expression of results Calculate the viscosity of the latex, expressed in milli
49、pascal seconds (centipoises), using the appropriate factor given in Table 2. Table 2 Factors necessary to convert readings on the scale 0 to 100 to millipascal seconds (centipoises) Spindle number Factor L1 L2 or R1 L3 or R2 R3 1 5 20 50 10 Precision See Annex B. 11 Test report The test report shall include the following particulars: a) a reference to this International Standard; b) all details necessary to identify the test sample; c) the resul
