ISO 3689 Paper and Cardboard - Determination of Burst Strength after Immersion in Water

In the ISO 3689 standard published by the International Standards Organization (ISO), a test method is defined for determining the wet strength of paper and cardboard by measuring the bursting strength after immersion in water for a certain period of time. In principle, this method is applicable to most paper and board types, provided that a suitable dipping time is agreed between the parties involved. However, if the sample is tested again after a while, different results are obtained.

For the purposes of the ISO 3689 standard,

• The expression burst strength after immersion for a certain hour refers to the limiting resistance offered by a single sheet of paper or cardboard after being immersed in water for a certain hour, under the specified test conditions, against a uniform pressure applied at right angles to its surface up to the point where it breaks.
• The expression burst strength retention after immersion for a certain hour expresses the percentage of bursting strength of a single sheet of paper or cardboard after immersion in water for a certain hour.

Mechanical strength properties such as burst strength and tear strength are measured using equipment in the physical testing laboratory. The main product groups tested are:

• Raw materials such as paper, tissue paper, folding cardboard, corrugated cardboard, composites and the like
• Finished products such as boxes, folding cartons, cartons, books, brochures, tissue paper products, blister packs, labels and so on

These tests are performed after standardized conditioning or after heat, humidity or light aging.

When cellulose fibers or unsized papers are exposed to a liquid, a number of changes occur depending on the degree of penetration of the liquid into the fibers and can change the intrafiber or interfiber bonds. For example, the tensile strength of paper decreases in all liquids. In the more inactive fluids, this happens without swelling.

There are numerous packaging standards developed by ISO . ISO 3689 is one of them.

Among the numerous test, measurement, analysis and evaluation studies it provides for businesses in various sectors, our organization also provides test services for bursting strength after immersion of paper and cardboard in water, within the scope of ISO 3689 standard, with its trained and expert staff and advanced technological equipment.