Simplified Method Of Measuring Tack Of Pressure Sensitive Adhesives

By Leonard Thibodeau, Texture Product Manager, Brookfield Engineering Laboratories, Inc.

The procedure for measuring tack of pressure sensitive adhesives is fully described in some ASTM methods. The definition for tack is the maximum force required to break contact from the adhesive surface as the test probe pulls away. The units of force should be stated in kPa. This result is dependent upon several fac­tors:

• The surface area of the probe
• The finish on the face of the probe
• The thickness of the adhesive layer
• The force with which the probe contacts the adhesive
• The length of time that contact is maintained prior to pulling away
• The Speed at which the test probe is pulled away