What is Peel Adhesion?
Peel adhesion is the force required to remove a pressure sensitive adhesive from a testing plate or its own backing material. The goal of a peel adhesion test is to determine the adhesive strength level of the material between two materials and is measured in ounces per one inch of tape. The results of this test are surface dependent and are influenced by the testing angle which is typically 90 or 180 degrees.
Peel adhesion strength is measured for many purposes and uses different methods. One of the common one used is the PSTC-101; it’s a standard test method to measure peel adhesion strength in pressure sensitive tapes. PSTC-101 is a Harmonized International Standard. These types of standard tests are created under the understanding that societies and other technical bodies from a variety of countries have agreed to consolidate their similar standards under the auspices of ISO.
PSTC-101 Test Procedure
PSTC-101 is very similar to the test methods involved in ASTM D3330. As in ASTM D3330, PSTC-101 defines Methods A through F to measure adherence with 180 degree and 90 degree peel tests. The following tests should be performed:
- - Method A is a 180 degree peel test of test tape to a standard steel panel
- - Method B is a 180 degree peel test of tape to its own backing
- - Method C is a 180 degree peel test of double-sided stick tape to a standard steel panel
- - Method D is a 180 degree peel test of single or double-sided stick tape to its liner
- - Method E is a 180 degree peel test of transfer tape adhesion to a standard steel panel
- - Method F is a 90 degree peel test of tape to a standard steel plate or other surface of interest
PSTC-101 test methods may not be appropriate to test tapes having either relatively stiff backings, stiff liners, or backing showing high stretch at low forces. These characteristics will result in a high variability for the test response which is not a true indication of the real nature of the adhesive bond.