What is ISO 5626 - Folding endurance of paper about?

Fold endurance measures the durability of paper when repeatedly folded under constant load. determining how many times the paper can be folded until it breaks. The folding strength is quoted as the number of double folds and the folding endurance is the log10 of the number of double folds.

ISO 5626 specifies the methods for the determination of folding endurance of paper using Köhler Molin, Lhomargy, MIT and Schopper testers. ISO 5626 sets out the conditions to be observed when using these instruments and gives the precautions to be taken in using each instrument. When operated with the standard loads, the Köhler-Molin, Lhomargy and Schopper methods are applicable to paper up to 0,25 mm thick and have a tensile strength greater than 1,33 kN/m.

Interpretation of the results is complicated by the fact that the different types of instruments included in ISO 5626 will give different numerical results for the same test material and they can produce dissimilar rankings for different test materials.

Who is ISO 5626 - Folding endurance of paper for?

ISO 5626 on folding endurance of paper is useful for:

The paper and board industry
Paper mills
Paper manufacturing companies
Suppliers and distributors for paper
Laboratories for paper testing
Paper analysis researchers

Why should you use ISO 5626 - Folding endurance of paper?

A number of instruments for determining the folding endurance of paper are in existence, the most commonly used being the Köhler Molin, Lhomargy, the MIT and the Schopper instruments. ISO 5626 is based upon these four types of instruments. The results obtained with the instruments described are very sensitive to atmospheric conditions under which the test is carried out, particularly humidity.

All four types of instruments are normally motor-driven. ISO 5626 provides you with appropriate measures, which need to take care of by the manufacturer or user to minimize the effects upon results of vibration and heat from the motor.

ISO 5626 allows the results to be reported as either folding endurance [the logarithm (to the base 10) of the number of double folds] or the fold number (the antilogarithm of the folding endurance). ISO 5626 give information on the instruments and their maintenance and calibration.

ISO 5626 guidelines help you to measure the durability of paper and assess the ageing characteristics of a paper by measuring folding endurance.

BS ISO 5626:1993

Paper. Determination of folding endurance

Current, Under Review

Published:

15 Mar 1994