Cobb Tester | Water Absorption Testing Device for Paper & Cardboard

DESCRIPTION / TECHNICAL SPECIFICATIONS

How a paper or paperboard interacts with water is one of the most fundamental properties that dictates its real-world performance. From a box's ability to withstand environmental humidity, to the drying speed of water-based inks, to the bond strength of adhesives on packaging, everything depends on the degree of water absorption at the surface. We present the Cobb Tester, an essential instrument that uses an industry-standard method to quantitatively measure the water absorbability of paper and paperboard.

This device operates on the simple, reliable, and universally recognized Cobb test method. A cylindrical ring with a standard internal area (typically 100 cm²) is securely clamped onto the surface of the test specimen. A specified volume of water is poured into the ring and allowed to contact the sample surface for a defined period. After this time, the water is poured out, and the sample surface is blotted with a standardized heavy roller to remove any excess water. By weighing the sample before and after the test, the weight gain due to absorbed water can be calculated. This value, known as the Cobb value, provides an accurate measure of the material's surface water absorbency.

Built with a robust and straightforward mechanical design, this instrument ensures long-term reliability and repeatable results with minimal maintenance. Its simplicity of operation makes it an ideal tool for rapid, routine testing in a busy production environment as well as in a quality assurance laboratory. Every component, from the test cylinder to the blotting roller, is crafted to meet the parameters of standard test methods, ensuring your results are consistent and comparable to global industry benchmarks.

The Cobb Tester is a must-have device for paper manufacturers (especially for kraftliner, testliner, and medium papers), the packaging converting industry, and printing companies. The data it generates is critical for controlling the sizing process during paper production, predicting the behavior of inks and adhesives on a surface, and ensuring the integrity of packaging in humid conditions. Take control of your material's most critical properties and ensure consistent product quality with this fundamental testing instrument.