Tensile Test Results: Adhesion of Tape to Plastic Surface

[TensileTest]

TL;DR Summary

How should I interpret these results?

Hello,

I am currently writing my thesis, where I have to investigate if a surface treatment increases the adhesion (between tape and a plastic surface). For this purpose, I have among other tests, performed a tensile test between the tape and plastic surface. The tensile test can be separated in two:

1)To test the adhesion between tape and plastic surface (when the plastic surface has not been treated).

2) To test the adhesion between tape and plastic surface (when the plastic surface HAS been treated)

My results are:

1) The mean for the maximum load is: 29 Newton. It was possible to pull the tape 10-20 centimeters of the plastic surface, before the tape broke.

2) The mean for the maximum load is: 25 Newton. It was possible to pull the tape 5 centimeters of the plastic surface, before the tape broke.

I think that the test results from ”2” (with surface treatment) indicates that the surface treatment increased the adhesion. But the mean for the maximum load is smaller here. I do not understand. What can I concluded from these results and how can I explain them?

 

[JBA]

A diagram or picture of your test method would be helpful in understanding it.
With regard to adhesive qualities, as I understand it, there are two basic types of adhesion, one is penetration of the adhesive into the contacting surface(s), for which a textured surface may be helpful; the other is electrostatic adhesion, for this a smoother surface with more contact area may be better.

 

[Baluncore]

I would expect the tape to stretch more than the plastic backing. The force then, is that needed to peel or separate the width of the tape, not the contact area of the tape. Speed will be important as energy flow is needed to break the bond as the tape is progressively released.

I would expected the test to be a continuous process. I would like to know why the tape broke.

Maybe you could describe the testing geometry and procedure better.