ISO 12625-5:2016 specifies a test method for the determination of the wet tensile strength of tissue paper and tissue products after soaking with water, using a tensile-strength-testing apparatus operating with a constant rate of elongation.
Currently, two types of tensile-strength-testing apparatus are commercially available, one where the test piece is positioned vertically and, for the other, horizontally. This document applies for both. For vertical tensile-strength-testing apparatus, a device which is held in the lower grip of the tensile-strength-testing apparatus, called a Finch Cup, is used to achieve the wetting. For horizontal tensile-strength-testing apparatus, the soaking device is placed between the clamps.
In cases where impurities and contraries have to be determined, ISO 15755 applies for these detections in tissue paper and tissue products.