Folding endurance (double fold) testing

Fold endurance measures the durability of paper when repeatedly folded under constant load. A Schopper double fold tester is used by Pira to determine the number of times a 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.

The test is primarily used for testing papers that are frequently handled such as currency (bank note) papers, maps and wrapping papers. The ageing characteristics of a paper can be assessed by measuring fold endurance before and after accelerated environmental ageing.

Folding endurance testing is performed to the British standard and International standard BS ISO 5626, and is included in Pira's Paper Proficiency Service.

Expert Profile

  • Doug joined Pira in 1989 and has 20 years experience in the physical testing of packaging and packaging materials. He heads a team specialising in packaging and print related technical investigations. In 2004 Doug gained his postgraduate degree with distinction in Packaging Technology from Brunel University.

    Doug Leatherdale
    Doug Leatherdale

    Head of Physical Testing

    Pira International

    +44 1372 80 2108

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