One method to measure the tack force / strength of an adhesive is to perform the “Loop Tack” test method described in specification ASTM D6195. The adhesives tested with this test are typically pressure sensitive adhesives (PSA) applied to films, labels, tapes, and stickers where the initial tack force is an important characteristic of the product. The specification describes two ways to perform the test. One method (Method B) uses a single purpose machine. Although the simplicity of one dedicated machine is nice, the loop tack method is uncommonly the sole test of any manufacturer. The other method (Method A) uses a universal testing machine otherwise known as a tensile testing machine. Using this method provides you with accurate test results, the same ease of use as the single purpose machine, and also allows you to use the universal testing machine for many other common adhesive and material tests such as 90 degree peel adhesion tests, 180 degree peel adhesion tests, and standard tensile strength testing. If you only need to perform the loop tack test you should consider a single purpose machine and follow Method B. If you have a tensile testing machine, or need to perform other adhesive and material tests, you should follow Method A.
This is a short video of the test followed by a simple summary to help determine if this test is right for your application. Please read the entire ASTM specification if you decide to perform the test.
Procedure:
1. Make a loop with your tape with the adhesive on the outside of the loop.
2. Place the loop in the top grip of the universal testing machine.
3. Bring the loop into contact with a 1″ cube fastened to the bottom of the universal testing machine.
4. Remove the tape from the 1″ cube fixture.
5. Report the peak and/or the average force during removal.
Test performed on an ADMET eXpert 7601 universal testing machine.
Test report generated from ADMET’s MTESTQuattro testing software.
