Peeling Direction and Adhesive Force: Explained

• jangheej
It's interesting to think about why this might be.In summary, the left diagram shows a force that is applied directly to the edge, while the right diagram has a force that is applied to the entire adhesive strip. The left diagram has more resistance because the remaining adhesive does not allow for easy removal.

jangheej

peeling direction...?

when I tried to peel a tape off the surface, I realized that it requires much larger force to pull in the direction shown in the left picture. Why is that?

if we think about it, the adhesive force is caused by the adhesive filament that stretches and breaks as we apply force. But if the angle of pulling is the same, it seems there should be no particular reason why the left case would be harder to peel the tape off.

And also, why does the elastic deformation become more evident in the left case?

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Interesting, something I've never really thought about.

If I had to put an initial guess without really thinking too deeply about it, I'd say it's to do with the concentration of force.

On the right, the force is applied directly to the edge only. Equal force on each tape, but the pressure resulting from the angle of pull is greater in the right hand diagram.

What about if we were to consider the extreme case of zero degrees pulling angle - with left hand diagram we would be attempting to pull all the tape off the table in one go whereas with right hand we would still be doing it sequentially. So it's the vertical force component which is constant in both cases but as I think this extreme case shows us, it is also he horizontal component that helps remove the tape, which is only effective when we pull it in the correct direction

Just my 2c :-)

On the right hand pic, one is only pulling away from the surface a very small amount of total adhesive at a time, and the remaining tape does not resist this.
On the left hand pic, the remaining tape does resist. This resistance can be substantial.

1. What is peeling direction and why is it important in adhesives?

Peeling direction refers to the direction in which an adhesive is pulled or peeled away from a surface. It is important because the peeling direction can affect the strength and durability of the bond between the adhesive and the surface it is applied to.

2. How does peeling direction affect the adhesive force?

The peeling direction can affect the adhesive force in several ways. When an adhesive is pulled in the same direction as its bond, it can create a stronger bond due to the alignment of the adhesive molecules. However, if the peeling direction is perpendicular to the bond, it can cause the adhesive to fail and reduce the adhesive force.

3. What factors determine the peeling direction in adhesives?

The peeling direction in adhesives is primarily determined by the type of adhesive being used, the properties of the surface it is applied to, and the force applied during peeling. Additionally, the angle at which the adhesive is applied and the environmental conditions can also play a role in determining the peeling direction.

4. Can the peeling direction be controlled in adhesives?

Yes, the peeling direction can be controlled to some extent in adhesives. For example, using a backing material or applying pressure during bonding can help to ensure that the adhesive is pulled in the desired direction. However, some factors such as surface properties and environmental conditions may be more difficult to control.

5. Is the adhesive force affected by the speed of peeling?

Yes, the speed of peeling can affect the adhesive force. In general, slower peeling speeds can result in a stronger bond, as it allows more time for the adhesive molecules to align and form a stronger bond with the surface. On the other hand, faster peeling speeds may result in a weaker bond and reduced adhesive force.