There are various ways to measure how paper and board responds to application of water or oil. These properties can be controlled so that the material will get the right absorbency for its use.
The film shows the most common test methods for water or oil absorption, namely, Emtec, the contact angle and Bristow methods as well as Cobb 60 and oil absorbency according to Cobb-Unger.
The Emtec method shows how quickly a liquid penetrates into the material and the absorbency process can be shown in a diagram.
When the contact angle is measured during the absorbency process, it can be seen how quickly one single drop is absorbed. By measuring the contact angle of two liquids the material's surface energy is determined. The methods of contact angle measurement and Emtec is important for water-based printing, for example ink jet printing.
Finally, the oil absorption Cobb method is an interesting method for testing food packaging where penetration of oil and fats should be as slow as possible. The applications are for oil based printing inks as well as for packages where food is heated in an oven or in a microwave oven.
Contact: Pia Renström, +4670 381 56 57 E-mail