1 Scope
This part of ISO 11093 specifies a method for the determination, by the three-point method, of the flexural modulus of cylindrical paper and board cores which meet the following criteria:
| — | internal diameter: | 50 mm to 350 mm; |
| — | minimum wall thickness: | 0,05 × internal diameter, but not less than 10,0 mm; |
| — | minimum length of core: | 10 × internal diameter, but not less than 1 000 mm. |
If the flexural modulus has to be used for the calculation of a paper core’s natural frequency, ISO 11093-8[2] applies instead of this International Standard.