Adhesion is the force that resists the separation of two bodies in contact. An adhesion test measures the adhesive characteristics of a product by measuring the forces to separate the product from the test surface which it comes into contact with. Adhesiveness ('Stickiness') is most commonly measured with a cylinder probe, which is pressed (application of compression), onto the surface of the sample after which the force to pull the probe off it is measured. The higher the force to separate these surfaces, the more adhesive is the product. The distance the probe needs to be pulled away from the product before the two surfaces are separated will also indicate its viscoelastic behaviour, and depending upon the product, its ‘tailing’ or ‘stringiness’ characteristic.
