ISO 535 Water Absorptiveness Testing
ISO 535 package testing determines the water absorptiveness of paper and board. As an ISTA and ISO 17025 certified lab, we realize the importance of ISO 535 testing. Meeting the ISO 535 water absorptiveness testing requirements can be difficult. We understand the challenges and guide companies through the process.
Keystone Package Testing partners with customers to achieve package compliance. Our accurate test reports are delivered quickly. We create an accurate test plan to eliminate expensive over-testing. Keystone takes a consultative approach throughout the entire test program.
Summary of Cobb Method Information
The purpose of this method is to determine the water absorptiveness of sized paper and board. This Cobb testing method also includes corrugated fibreboard under standard conditions. It may not be suitable for paper of grammage less than 50 g/㎡ or embossed paper.
A test piece is weighed immediately before and immediately after exposure for a specified time of one surface to water, followed by blotting. The result shows an increased mass expressed in grams per square meter.
This method is not intended to be used for precise evaluation of the writing properties of paper. Although, it does give a general indication for use with aqueous solutions.
Scope of ISO 535 Water Absorptiveness Testing
Both surfaces that come into contact with the test piece are dried before commencing each test. The test pieces are weighed to the nearest milligram. Then, they are placed to be tested with the uppermost surface on the base plate. This procedure is according to the water absorbency of the paper and board under construction.
At least 10 test pieces of sufficient size to exceed the diameter of the cylinder by at least 10mm from any edge are cut from the specimen. It must be ensured that the test area is avoided by contact of hands. Also, the area must be free from visible folds, creases, cracks or other defects. If watermarks are present, these areas are avoided as well.
Test plates will be rejected if they have been penetrated through by the water. They will also be rejected if they show signs of leakage or show excess water after blotting. If no reduced time is fitting, this ISO 535 method is not suitable.
Significance of ISO 535 Cobb Method
When mounting the test piece, the upper edge of the surface which will come into contact with the test piece is dried before the start of the test. The cylinder is placed with the machine edge in contact with the test piece and clamped firmly to prevent any leakage of water between it and the test piece.
Within this national standards method, the test report will consist of general information. Information includes the date, time, location, and specific test engineer. Other information may include, but not limited to, reference to this international standard. Conditioning atmosphere used, and any circumstances or factors which may be affected or influenced by the results.
Expert ISO 535 Paper and Board Package Testing
Keystone can accommodate flexible and rigid packages of all sizes, including large pallets. We have a full lab of test equipment which permits us to provide short lead times on scheduling. In addition to ISO 535 testing, Keystone also has a full scope of expertise including sterile barrier, cold chain, and inclined impact.
Are you ready to get started? We are. Contact us and learn first hand why so many companies partner with Keystone to achieve their paper, board, and related product certification needs