ISO 9773 pdf download.Plastics — Determination of burning behaviour of thin flexible vertical specimens in contact with a small-flame ignition source
7 Specimens
7.1 It is possible that the results of tests carried out on test specimens taken from materials of different densities, colours, thicknesses, melt flow abilities and directions of anisotropy, or with different additive or filler/reinforcement contents, will be different. For materials with properties or compositions which vary over a range, the test specimens shall be representative of the whole range.
7.2 Test specimens with densities, melt flow abilities and additive or filler/reinforcement contents at the extremes of the range shall be tested and, if the test results yield the same flame test classification, all specimens within the range shall be considered representative of the range. If the burning characteristics are not essentially the same, the results of the evaluation shall be considered to apply only to the materials with the densities, melt flow abilities and additive or filler/reinforcement contents tested. Additional test specimens with intermediate densities, melt flow abilities and additive or filler/reinforcement contents shall be tested to determine the range of applicability.
7.3 Uncoloured test specimens and test specimens with the highest level of organic and inorganic pigment loading shall be tested and, if the test results yield the same flame test classification, all specimens with this colour range shall be considered representative of the range. If a material contains pigments which are known to affect the flammability characteristics, specimens containing these pigments shall also be tested. Thus the test specimens tested shall be those that a) contain no colouring; b) contain the highest level of organic pigments; c) contain the highest level of inorganic pigments;d) contain pigments which are known to adversely affect flammability characteristics.
7.4 All specimens shall be cut from a representative sample of the material (sheets or end products). After any cutting operation, care shall be taken to remove all dust and any particles from the surface. Cut edges shall have a smooth finish.
7.5 The standard test specimen shall be 200 mm ± 5 mm long, 50 mm ± 2 mm wide and a maximum of 0,25 mm thick. Measure the thickness of each to the nearest 0,01 mm and note the measurements. NOTE 3 Tests made on test specimens of different thicknesses or directions of anisotropy may not be comparable.
7.6 Mark each specimen across its width with a line at 1 25 mm ± 5 mm from one end (the bottom end). Wrap the longitudinal axis of the specimen tightly around the longitudinal axis of the mandrel to form a lapped cylinder with the 1 25 mm line exposed. Secure the overlapping portions of the specimen within the upper 75 mm segment above the 1 25 mm mark and at the upper end of the tube with pressure-sensitive adhesive tape. Then remove the mandrel. NOTE 4 For stiff specimens, the pressure-sensitive tape may be reinforced or replaced by nichrome wire wound around the top 75 mm of the specimen (see Figure 1 ). 7.7 Prepare a minimum of 20 specimens. It is advisable to prepare additional specimens for any retesting which may be necessary.