The water content of all kinds of paper products is measured as moisture. High or low humidity in these products causes negative results in terms of product quality. In these products, as the humidity decreases, the brittleness increases. If the humidity is high, the water absorption rate of the products decreases. Moisture in paper products can be caused by storage conditions as well as by the production environment. Since the paper is physically water-loving, it continues to absorb moisture in high-humidity environments. Otherwise, the paper starts to emit moisture, ie it dries.

It is necessary to pay attention to the storage conditions of the paper products in order to achieve the expected absorption rate. Optimal relative humidity in storage conditions is 55 percent.

The resistance of paper products to water or the level of acceptance of water is called the Cobb value. The Cobb value is the value in grams per square meter of the amount of water absorbed by a square meter of paper surface over a period of time. According to globally accepted standards, this period is as follows:

• 120 seconds on labels and paperboard
• 60 seconds on offset, photocopy and coated paper

This value must be kept within a certain range for the quality of the paper.

Authorized laboratories carry out tests and analyzes to determine the absorption rates of paper products within the framework of specific tests. These studies are based on standards published by domestic and foreign organizations. The standards considered to determine the absorption rates of paper products are:

• TS 11668 Paper towels

This standard specifies the characteristics and types of towels made of soft tissue paper, sampling and testing methods and marking criteria.

• TS EN ISO 12625-8 Soft tissue and products - Part 8: Water absorption time and water absorption capacity, basket dipping test method

This standard covers basket dipping test method for determining water absorption time and water absorption capacity of soft tissue and similar products.