Core Standard
International testing protocols define the methods for determining the physical dimensions and mechanical properties of cylindrical paper and board cores. Adherence to iso 11093 provides a uniform framework for measuring wall thickness, internal diameter, moisture content and core density of the spiral wound tubes used in the paper industry. This standard ensures that the cores can withstand the high radial pressures and torque requirements of modern winding and unwinding equipment.
Dimensional Verification
Precision in the manufacturing of the core ensures compatibility with the chucks and mandrels of high speed printing presses. The procedures outlined in iso 11093 specify how to account for the hygroscopic nature of paper, which can cause cores to expand or contract based on ambient humidity. Measuring the straightness and out of roundness helps prevent machine vibration and web tension fluctuations during the conversion process.
These metrics are necessary for maintaining the structural integrity of the heavy paper rolls during storage and maritime transport.
Strength Requirement
Dynamic testing of the core includes measuring the flat crush resistance and the bending stiffness to predict performance under load. Since iso 11093 covers the testing of core compressive strength, it allows mills to specify the grade of board needed to prevent core collapse in the bottom tiers of a warehouse stack. The standard helps avoid costly production downtime caused by crushed cores that cannot be mounted onto the unwind stand.
Reliability in these components is central to the safety of the logistics chain. Precise measurement according to the standard prevents mechanical failure that could lead to property damage or worker injury during the handling of multi ton rolls.
