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.