Slow rate recovery of polymers

[Speedy]

Folks,

This is a general question relating to slow rate recovery of polymers.

I am working with a material which deforms slowly under load. It is a very soft, low modulus material. The deformation or creep effects are beneficial to the functionality of the product(pressure relief).

My question concerns the shape recovery of the material when the load is removed. After the initial elastic recovery, will the material recover further due to the residual internal stresses? Is the rate of recovery similar to the original rate of creep deformation?

I had always assumed that all recovery is elastic and instantaneous, while the remaining deformation is permanent.

Appreciate any help!

 

I believe that your question is a little more complex than that. TIME and REPETITION are factors here. Material degradation over both the initial and continuous loading/unloading has an effect on the overall memory of the material. Not better knowing the formulation, load, deflection, application, etc, it's hard to better estimate the end-results. However, depending on the circumstances, one could expect both a relatively rapid (visually dramatic and observable) as well as a slower (less noticeable) return. Both typically become less dramatic and noticeable over repetitive loading/unloading.
Hope this helps.

 

[BLN]

You're also dealing with compression set. Over time under load, elastomers will achieve a permanent deformation known as compression set. Another factor to help determine the extent of set is the temperature.