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1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEWYHAPOAHAR OPl-AHbl3AMR l-IO CTAHAAPTM3AMM Plastics - Determination of the effects of exposure to damp heat, water spray and salt mist Plastiques - D the preparation of test specimens
2、. It also only gives general guidance on the properties to be evaluated. Specific details are given in the various IS0 and IEC Publica- tions. In these conditions not only water absorption or leaching of some ingredients of the composition may be observed but also degradation phenomena due to hydrol
3、ysis, exudation of plasticizers, etc. For the expression of results, the present International Stan- dard follows, as far as possible, the same criteria adopted in the existing test methods .for the exposure to chemicals (see IS0 175) and to natural weathering or artificial light (see IS0 4582). It
4、may also be desirable sometimes to evaluate the behaviour of materials in the presence of a highly corrosive electrolyte, such as a sodium chloride solution (salt mist), which is the principal aggressive agent present in marine environments and of par- ticular importance in the case of nautical appl
5、ications. It is well known that sodium chloride has no noticeable action on the polymers that are the basic components of plastics, and that salt solutions, owing to their higher osmotic pressure, are nor- mally absorbed by plastics to a lesser degree than pure water, but it cannot be assumed a prio
6、ri that they have no action on composite materials, containing fillers, reinforcing components or pigments, for instance. 0.4 These tests are intended to yield data about the effects of the described exposures on the materials; however, a direct correlation between the experimental results and the b
7、ehaviour in service is not to be inferred. 1 Scope and field of application 1 .l This International Standard specifies the exposure condi- tions of plastics to Furthermore, the evaluation of the effect of salt mist can be very important for finished or semi-finished articles which, while basically c
8、onsisting of plastic materials, do contain some metallic elements, such as moulded-in inserts, thin laminated foils, surface coatings applied by electro-plating or other pro- cedures, or, lastly, metal cores sheathed with plastics by extru- sion or by dipping in pastes or fluidized-bed powders. - da
9、mp heat, - water spray, - salt mist, and the methods for the evaluation of the change of some significant characteristics after given exposure stages, 0.2 Methods and equipment for obtaining reproducible aggressive environments of. the shove types are well known 1.2 This International Standard is, i
10、n general, suitable for all plastics in the form of standard test specimens, and finished articles or parts thereof. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 00:25:53 MD
11、TNo reproduction or networking permitted without license from IHS -,-,- IS0 4611 : 1987 (EI 1.3 This international Standard considers separately methods for the determination of - change of mass, - change of dimensions and appearance, A change of physical properties. 2 References IS0 175, Plastics -
12、 Determination of the effects of liquid chemicals including water. IS0 233, Plastics - Compression moulding test specimens of thermoplastic materials. IS0 294, Plastics - Injection moulding test specimens of thermoplastic ma terias. IS0 235, Plastics - Compression moulding test specimens of tharmose
13、tting materials. IS0 2557-1, Plastics - Amorphous thermoplastic moulding materials - Preparation of test specimens with a defined level of shrinkage - Part 1: Test specimens in the form of parallelepipedic bars (Injection moulding and compression mouldingl. IS0 2557-2, Plastics - Amorphous thermopla
14、stics - Prepara- tion of test specimens with a specified reversion - Part 2: Plates. IS0 2818, Plastics - Preparation of test specimens by machin- ing, IS0 3205, Preferred test temperatures. IS0 3768, Metallic coatings - Neutral salt spray test (NSS test). IS0 4532, Plastics - Determination of chang
15、es in colour and variation in properties after exposure to daylight under glass, natural weathering or artificial fight. IEC Publication 68, Basic environmental testing procedures: 63-2-3, Test Ca: Damp heat, steady state. 66-2-l 1, Test Ke: Salt mist. 68-2-30, Test Db: Damp heat, cyclic (12 + 12”ho
16、ur cycle). 63-2-33, Test Z/AD: Composite temperature/humidity cyclic test. 3 Principle Determination of one or more properties before and after given periods of exposure in the specified environmental conditions, and observation of any change in appearance. If required, the determination of one or m
17、ore properties may be carried out after exposure and a subsequent drying treatment or a recondi- tioning treatment carried out with the aim of obtaining the same state of equilibrium with atmospheric humidity as that of the initial specimens. 4 General test conditions 4.1 Environmental conditions an
18、d equipment 4.1.1 Damp heat The preferred test conditions are those described by the IEC Publications referred to in 4.1.1.1 and 4.1.1.2. Different temperature and/or humidity conditions may be specified, however, in the relevant product specifications or by agree- ment between the interested partie
19、s. 4.1.1.1 Steady state test A suitable test method is specified in IEC Publication 58-2-3. The following conditions are specified: Temperature: 40 f 2 “C 4.1.1.2 Cyclic test If a cyclic test is required, the conditions specified in IEC Publication 66-2-30 can be adopted. This Publication specifies
20、12 h + 12 h cycles with temperature change from: 25 + 3T to al 40 k 2 OC b) 55 k 2 OC Relative humidity is maintained at (93 f 3) % at the higher temperature and not less than 95 % during the rest of the cycle. NOTE - For composite temperature/humidity cycles, with the addi- tion of a number of excu
21、rsions to sub-zero temperatures, some guidance can be found in IEC Publication 68-2-38. 4.1.2 Water spray The main difference between this exposure condition and that for damp heat/steady state (see 4.1.1) is the constant presence of the liquid phase, in the form of small water droplets. Suitable eq
22、uipment for obtaining these conditions is substan- tially identical to that for the salt mist exposure (see 4.1.3) and is described in the relevant specifications. Distilled or deionized water, having a pH between 6 and 7, shall be used instead of the salt solution. The temperature in the test enclo
23、sure shall be 40 f 2 OC. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 00:25:53 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 4511: 1987 (EI 4
24、.1.3 Salt mist b) after the exposure and subsequent drying or recon- ditioning Suitable equipment and procedure for the exposure to salt mist (or salt spray) are described in IS0 3766. The general operating conditions are as follows: Temperature inside the cabinet . . . . . . . . . . . . . . . 35 f
25、2 OC Sodium chloride solution: - concentration . . . . . . . . . . . . . . . . . . . . . . 50 f 5 g/l - PH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,5to7,2 The solution is prepared by dissolving sodium chloride of recognized analytical grade in distilled or deionized water.
26、 The purity requirements are specified in IS0 3766. Quantity of “mist” collected over a period of 24 h on a horizontal collecting area of 8 Ooo mm* . . . . . . . . 1 to 2 ml/h These conditions comply also with IEC Publication 68-2-l 1. NOTE - In this test, the 35 “C temperature value has been retain
27、ed, even though this value is not included among those recommended in IS0 3205, because it is specified in the IS0 3768 test referred to and by the majority of existing national standards. 4.2 Duration of tests The test duration shall be as specified in the relevant standard or as agreed upon by the
28、 interested parties, with reference to the intended application. It is recommended that the time periods be chosen from the following standard scale: 24,48,96,144,168 h and, for long periods: 1, 2, 4, 8, 16, 26, 52, 78 weeks. 4.3 T usually 4 h are sufficient for this purpose. 4.5.2 Test after exposu
29、re and drying or reconditioning After rinsing and wiping dry, the specimens shall be dried or reconditioned to equilibrium with the same atmospheric cond- itions as before the exposure (see 4.41, taking due account of the procedures described in A.3.1 and A.3.2 of the annex. Unless otherwise specifi
30、ed in the relevant product standard or agreed upon between the interested parties, the specimens shall be dried in an oven at 50 f 2 OC for 24 h and cooled to 23 f 2 OC in a desiccator. 5 Change of mass 5.1 General 5.1.1 In this type of test, the changes of mass are, at least partially, due to water
31、 absorption, and they are, therefore, par- ticularly influenced by the conditioning and drying/recondition- ing of the test specimens. It is important, therefore, that the precise conditions of test be specified in the relevant product specifications. Normally the specimens are weighed immediately a
32、fter ex- posure, rinsing and wiping dry, or are treated as described in 4.5.1. If the determination of mass after drying or reconditioning is re- quired, the specimens shall be dried or reconditioned as specified in 4.5.2. NOTE - This test is not applicable to cellular materials. 5.1.2 The changes o
33、f mass are generally proportional to the surface area of the test specimens, but are influenced by their thickness. IMPORTANT - It is emphasized that the comparison of dif- ferent plastics- by means of this test is valid only if the test specimens used are of the same shape, the same dimensions and
34、in as nearly as possible the same state (of surface, internal stresses, etc. 1. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 00:25:53 MDTNo reproduction or networking permit
35、ted without license from IHS -,-,- IS0 4611 : 1967 (E) 5.2 Test specimens 5.2.4 Number of test specimens The test specimens may be obtained directly by moulding or by machining. In the latter case, the cut surfaces shall be smooth and shall not show any trace of charring that may be due to the metho
36、d of preparation. 5.2.1 Moulding and extrusion compounds The test specimens shall be in the form of a square of Xl f 1 mm side and 3 _+ 0,2 mm thick. Rectangular specimens having the same surface area (for example 100 mm x 25 mm, i.e. 2 500 mm21 may be used. The specimens may be cut from a sheet of
37、the same thickness, or prepared by compression or injection moulding or by extru- sion under the conditions given in the relevant specification for the material or under the conditions prescribed by the supplier of the material. Moulding materials may be, alternatively, directly moulded in a mould o
38、f the prescribed dimensions. The state of internal stress, if necessary, shall be determined according to IS0 2557-l and/or IS0 2557-2, as applicable. NOTE - The general principles for preparing moulded and machined test specimens are the subject of the following International Stan- dards: IS0 293,
39、IS0 294, IS0 295, IS0 2557-1, IS0 2557-2, IS0 2818. 5.2.2 Sheet The specimens shall be 50 + 1 mm square or rectangular, having the same surface area, and shall be cut from the sheet under test. If the nominal thickness of the sheet under test is equal to or less than 25 mm, the thickness of the test
40、 specimen shall be the same as that of the sheet. If the nominal thickness is greater than 25 mm and in the absence of special provisions in the relevant specification, the thickness of the test specimen shall be reduced to 25 mm by machining on one surface only. The machined surface shall not be di
41、rectly exposed to water or salt spray. A complete description of the machining, if any, shall be in- cluded in the test report. 5.2.3 Semi-finished and finished products (other than sheets) The specimens shall be as similar in shape and size as possible to the specimens described in 5.2.1, and be pr
42、epared according to the product specification or as agreed upon between the interested parties. If any machining is necessary, a complete description thereof shall be included in the test report. At least three specimens shall be tested. 5.3 Conditioning See 4.4. 5.4 Procedure 5.4.1 Determine the ma
43、ss (ml) of each specimen to the nearest 0,001 g. 5.4.2 Expose the specimens to the test environment chosen from those listed in clause 4. 5.4.3 Rinse, if necessary (for example in the case of exposure to salt mist), and wipe the specimens dry. 5.4.4 Immediately determine the mass (1712) of each spec
44、imen to the nearest 0,001 g. 5.4.5 Dry or recondition the specimens, if required, according to 4.5.2 and determine the mass (7ns) of each specimen to the nearest 0,001 g. 5.5 Expression of results 5.5.1 The change of mass per.unit area, in grams per square metre, is given by the formula m2 - ml m3 -
45、 m7 or S S respectively where ml, m2 and ma are as defined in 5.4.1, 5.4.4 and 5.4.5; S is the initial total surface area (including the edges of the specimens) in square metres. 5.5.2 The change of mass, as a percentage, is given by the formula m2 - ml x100 or m3 - ml x IO0 resoectivelv. ml ml The
46、change is positive for increase of mass and negative for reduction of mass. 5.5.3 Calculate the mean value of the test results for all the specimens from a given sample. 6 Change of dimensions and appearance 6.1 General Change of dimensions may result from either volume changes due to water absorpti
47、on or leaching of some components, or to relaxation of internal moulded-in stresses, or both. 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 00:25:53 MDTNo reproduction or net
48、working permitted without license from IHS -,-,- IS0 4511: 1987 (El It is important, therefore, that the precise conditions of test be specified in the relevant product specifications. For anisotropic materials, such as calendered or extruded sheets or extruded rods, the changes in linear dimensions
49、 in the machine direction (lengthwise) and in the transverse direction (crosswise) may be different; it is therefore necessary to deter- mine the changes in both directions. Where it is desired to differentiate between the effect of the relaxation of moulded-in stresses and that of the action of water, the test may also be performed using a set of annealed specimens. 6.2 Test specimens Prepare the test specimens as described in 5.2. Fo