BS EN ISO 175:2010 pdf free download – Plastics – Methods of test for the determination of the effects of immersion in liquid chemicals.
If the nominal thickness is greater than 25 mm, and in the absence of special provisions in the relevant specification, the thickness of the specimen shall be reduced to between 1,0 mm and 1,1 mm or between 2,0 mm and 2,1 mm by machining one face only.
NOTE For Fickian diffusion, the time to reach equilibrium increases in proportion to the square of the specimen thickness. In particular, 25-mm-thick specimens will typically require more than 5 years to reach equilibrium.
5.3.4 Tubes and rods
5.3.4.1 Tubes
If possible, reference shall be made to the relevant International Standards for the material under test2). In the absence of specific International Standards, the specimen shall be a piece of tube of length (60 ± 1) mm, obtained by cutting it at right angles to its longitudinal axis.
For tubes of outside diameter greater than 60 mm, a length of (60 ± 1) mm shall be cut and the test specimen prepared from this length by making a cut along each of two planes containing the longitudinal axis of the tube, so as to give a developed width of (60 ± 1) mm when measured on the outer surface.
5.3.4.2 Rods
For rods of diameter less than or equal to 60 mm, the test specimen shall be a piece of the rod of length (60 ± 1) mm, obtained by cutting it at right angles to its longitudinal axis.
For rods of diameter greater than 60 mm, in the absence of any specification agreed between the interested parties, the test specimen shall be a (60 ± 1) mm length of the rod with its diameter reduced to (60 ± 1) mm by machining concentrically.
5.3.5 Profile sections
In the absence of specific International Standards, cut a (60 ± 1) mm long piece of the profile section and use this as the test specimen. Ensure the thickness of the piece approximates as closely as possible to 1,0 mm to 1,1 mm, if necessary by machining one face only. The exact thickness to be achieved and the machining conditions shall be subject to agreement between the interested parties.
5.4 Determination of changes in mass3)
5.4.1 Procedure
5.4.1.1 Conditioning
Condition the specimens in accordance with 4.5 and select the test conditions in accordance with 4.1 to 4.3.
5.4.1.2 Measurement of initial mass
Determine the mass m of each specimen to the nearest 1 mg in the case of specimens of mass greater than or equal to 1 g, or to the nearest 0,1 mg in the case of specimens of mass less than 1 g.
Immerse the specimens in the test liquid as indicated in 4.6.2.
5.4.1.3 Measurement of mass immediately after removal from the liquid
After removal from the test liquid, rinse and wipe the specimens in accordance with 4.6.3 and place each specimen in a tared weighing bottle, stopper it and determine the mass of the specimen in2 to the nearest I mg or 0,1 mg as appropriate (see 5.4.1.2).
If the liquid used for the test is volatile at ambient temperature, the time during which the specimen is exposed to the air shall not exceed 30 s. If it is necessary to continue the test after weighing (i.e. when testing as a function of time), immediately replace the specimens in the test liquid and put the beakers back in the thermostatically controlled enclosure.
5.4.1.4 Measurement of mass immediately after removal and after drying
After carrying out 5.4.1.3, remove the specimens from the weighing bottles and dry them in the oven at the specified temperature to constant mass. For 1-mm-thick specimens dried at (50 ± 2) °C, this usually takes 2 h. Allow the specimens to cool if necessary, recondition them in accordance with 4.5 and determine the mass in3 of each specimen.
NOTE The reconditioning stage may be omitted by agreement between the interested parties.
5.4.1.5 Measurement of mass only after drying
Alternatively, immediately after removal from the test liquid, rinse and wipe the specimens in accordance with 4.6.3, then place them in the oven and proceed as in 5.4.1.4.