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1、INTERNATIONAL STANDARD IS0 1110 Third edition 1995-02-01 Plastics - Polyamides - Accelerated conditioning of test specimens Plastiques - Polyamides - Conditionnement accd6rb d 6prouvettes Reference number IS0 11 IO:1 995(E) IS0 1110:1995(E) Foreword IS0 (the International Organization for Standardiz
2、ation) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be
3、 represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International S
4、tandards adopted by the 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. International Standard IS0 1110 was prepared by Technical Committee ISO/TC 61, Plastics, Subco
5、mmittee SC 9, Thermoplastic materials. This third edition cancels and replaces the second edition (IS0 1110:1987), which has been technically revised. 0 IS0 1995 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, el
6、ectronic or mechanical, including photocopyrng and microfilm, wrthout permission in writing from the publisher. International Organization for Standardization Case Postale 56 l CH-1211 Geneve 20 l Switzerland Printed in Swrtzerland ii -,-,- 0 IS0 IS0 1110:1995E) Introduction Various properties of po
7、lyamides (PA) depend upon their moisture content. Reproducible values of these properties can only be obtained with speci- mens having a specified moisture content. Such specimens are obtained by conditioning, i.e. by allowing them to reach equilibrium in an atmos- phere with a specified temperature
8、 and relative humidity. The rate of moisture absorption and, therefore, the rate of conditioning, is a function of the temperature. This rate is very low at room temperature. For example, a 4 mm thick test specimen of PA66 requires more than a year to attain its equilibrium moisture content in stand
9、ard atmosphere 23/50 (see IS0 291). To condition specimens in a relatively short period of time, higher temperatures are required. Such a method for accelerated conditioning is presented in this International Standard. III INTERNATIONAL STANDARD Q IS0 IS0 1110:1995(EI Plastics - Polyamides - Acceler
10、ated conditioning of test specimens 1 Scope This International Standard describes a method for the accelerated conditioning of test specimens of polyamides and copolyamides. It is applicable to grades containing fillers and other additives, but not to grades containing more than 2 % (m/m) extract- a
11、bles. The equilibrium moisture content attained by this method is close to the equilibrium moisture content obtained in standard atmosphere 23/50. The values of mechanical properties obtained after accelerated conditioning in accordance with this method may dif- fer slightly from those obtained afte
12、r conditioning in standard atmosphere 23/50. chrometric temperature difference of 10 “C + 0,3 C) until moisture absorption by the specimen has reached at least 95 % of its equilibrium level. 4 Apparatus 4.1 Cabinet, with closed air circulation by a fan, capable of maintaining a temperature of 70 “C
13、within a tolerance of &- 1 “C and a psychrometric tempera- ture difference of 10 “C within a tolerance of + 0,3 “C, corresponding to a relative humidity of (62 + 1) %. 4.2 If a cabinet as described in 4.1 is not available: 2 Normative references 4.2.1 Oven, capable of maintaining the temperature at
14、70 “C + 1 “C. The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Intern
15、ational Standard are encouraged to investigate the possibility of applying the most re- cent editions of the standards indicated below. Members of IEC and IS0 maintain registers of cur- rently valid International Standards. 4.2.2 Closed container, for example a desiccator, partially filled with a sa
16、turated aqueous solution of potassium iodide in accordance with the general pro- cedure specified in IS0 483. Leave excess salt in contact with the solution throughout the conditioning. The specimens may be- come slightly discoloured by the absorption of iodine. 4.3 Analytical balance, accurate to 0
17、,l mg. IS0 291:1977, Plastics - Standard atmospheres for conditioning and testing. IS0 483:1988, Plastics - Small enclosures for con- ditioning and testing using aqueous solutions to maintain relative humidity at constant value. 3 Principle 5 Procedure Place the test specimens in the preheated cabin
18、et (4.1) or in the closed container (4.2.2) in the oven (4.2.1). By suitable means, for example racks, ensure that the surface of each specimen is almost com- pletely exposed to the surrounding atmosphere. The test specimens are stored in an atmosphere of 70 “C f 1 “C and (62 &- 1) % relative humidi
19、ty (psy- After conditioning for a period of time t, as indicated in table 1, remove the specimens from the cabinet or the container, allow them to cool for 1 h in standard 1 -,-,- IS0 1110:1995(E) 0 IS0 atmosphere 23/50 (see IS0 291) and weigh them to the nearest 0,l mg. Thereafter, continue the acc
20、eler- ated conditioning of the specimens and repeat the weighings, as above, at intervals of time t2 as indi- cated in table 1. The periods of time tl and t2 shall not be less than 1 day. the mass of the specimens versus the conditioning time shows that the values for group I may be used. When three
21、 consecutive weighings lie within a toler- ance of 0,l %, the conditioning is assumed to be completed (see note 1). Place the specimens in stan- dard atmosphere 23/50 for at least 1 h before testing. NOTE 1 Under these conditions, the specimens will have acquired a moisture content equal to at least
22、 95 % of the equilibrium value. A prolongation of the conditioning beyond this point will have no noticeable effect on the properties of the specimens. 6 Reference procedure In cases of PA not mentioned in table 1, use the val- In cases of dispute, the test specimens shall be con- ues of r, and t2 i
23、ndicated for group II, unless a plot of ditioned in the cabinet (4.1). Table 1 - Periods of time for accelerated conditioning Group I rl (days) PA in a cabinet in a container t2 (days) (4.1) (4.2.2) 6, 66, 11, 12, 6/66, 46 J- 3 h2 2 h2 -!- 8 h2 II 69, 610, 612, IND/INDT, 61/6T 2 3 h2 2h2 3 1 4 h2 I NOTE - h is the thickness, in millimetres, of the specimens. -I 2 -,-,- IS0 1110:1995(E) ICS 83.080.20 Descriptors: plastics, polyamide, test specimens, specimen preparation, condttiontng Price based on 2 pages -,-,-