Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:1:p7
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 1 (pt 7/43)
Character Range: 164764–167418

mm from the fixed end support. A load shall be suspended from the free end of the test specimen at a distance of 102 mm from the fulcrum as shown in Figure 21 below:

Figure 21

Method of setting up the sample

11.2.4.2. The load mass shall be 28.7 . t2 g where t is the thickness in mm of the test specimen. The resulting stress on the outer fibre of the sample is approximately 6.9 MPa.
 Example: For a 3 mm thick sample placed horizontally between a downward fixed edge and an upward fulcrum edge separated by 51 mm the applied downward load at 102 mm from the fulcrum is to be 258 g.
11.2.4.3. While the sample is stressed, one of the prescribed chemicals shall be applied to the top surface of the sample above the fulcrum point. The chemical shall be applied with a soft, 13 mm wide brush, wetted before each stroke. Ten individual strokes at 1 s intervals across the width of the sample, avoiding the end and edges, shall be required (see Figure 22).

Figure 22

Method of applying chemicals to the sample

11.2.5. Indices of difficulty of the secondary characteristics
                                                        Colourless   Tinted
 Colouring of the plastics coating or plastic glazing   1            2

 The other secondary characteristics are not concerned.
11.2.6. Interpretation of results
11.2.6.1. The test for resistance to chemical agents shall be considered to have given a satisfactory result if the sample does not exhibit any softening, tackiness, crazing or apparent loss of transparency.
11.2.6.2. A set of samples shall be considered satisfactory with regard to the test for resistance to chemical agents if one of the following conditions is met:
11.2.6.2.1. All the tests have given a satisfactory result;
11.2.6.2.2. One test having given an unsatisfactory result, a new series of tests carried out on a new set of samples has given a satisfactory result.
12. Flexibility test and fold test
12.1. Scope
 With this test has to be found out whether a plastic is to be classed into the categories of rigid or flexible plastics.
12.2. Test method
 From the material of the nominal thickness a rectangular flat sample 300 mm long and 25 mm wide is cut out and horizontally clamped into a clamping device in such a way that 275 mm of the length of the sample freely extend over the holding device. This free end shall be supported horizontally by an appropriate device until the test begins. Sixty seconds after removal of this support the vertical deviation of the free end is indicated in mm. If this deviation exceeds 50 mm a 180° fold test is performed subsequently. The sample is folded concisely, after that it is