ISO 527-2-2012 pdf download.Plastics – Determination of tensile properties- Part 2: Test conditions for moulding and extrusion plastics.
5.1 General
See ISO 527-1:2012. Clause 5, specifically 5.1.1 to 5.1.4.
5.2 Extensometer
For this part of ISO 527, a gauge length of 75 mm is preferred when a multipurpose test specimen is used.
A gauge length of 50 mm is also acceptable for quality-control purposes or where specified.
If strains are recorded only on one side of the test specimen, ensure that low strains are not falsified by bending, which may result from even faint misalignment and initial warpage of the test specimen and which generates strain differences between opposite surfaces of the test specimen.
NOTE Increasing the gauge length leads to higher accuracy, especially for the modulus determination, The absolute accuracy of the measurement of elongation required for a ±1 % accuracy of modulus determination is ±1,5 pm. This is less severe than the ii pm needed if a gauge length of 50 mm is used. Furthermore, necking outside of the gauge length will be less frequent.
5.3 RecordIng of data See ISO 527-1:2012, 5.1.6.
NOTE For the determination of the tensile modulus under the conditions v 1mm/mm, Lo = 75mm, L • 115 mm and r =0,0005mm, the recording frequency for the strain signal greater than or equal to 22 s-i would be appropriate according to ISO 527-1:2012, Equation 1. This frequency increases as the gauge length increases. With larger gauge length the absolute elongation measured by the extensometer Is larger for the same crosshead displacement, I.e the recording instrument will see more data points in the same time span.
6 Test specimens
6.1 Shape and dimensions
Wherever possible, the test specimens shall be dumb-bell-shaped types 1A and 1B, as shown in Figure 1 and Table 1. Type 1A shall be used for directly injection-moulded multipurpose test specimens, type 1 B for machined specimens. Type 1A may also be used for compression-moulded specimens. For the use of proportionally scaled miniaturized specimens, see Annex A and/or ISO 20753.
NOTE I At 4 mm thickness, specimen types 1A and lB are identical to the multipurpose test specimens according to ISO 3167. types A and B. respectively, and to types Al and A2 of ISO 20753.
For purposes where large numbers of test specimens are to be exposed in limited space, for example, during analysis of environmental influences due to radiation, heat and/or chemicals (see ISO 11403-3), small test specimens of type C of ISO 20753 can be used. In such cases, frequently only the relative change of strength is of interest, and specimens of type CW are particularly useful. To accommodate wall thicknesses of the final application, thicknesses different from those preferred in ISO 20753 may be used.ISO 527-2 pdf download.