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If you roll up a piece of paper and leave it for years it will stay rolled up. If you leave it rolled up for a minute it is easy to unroll. Of course this must be because the energy stored in that paper when it was first rolled was released in a way other than unravelling. So my question is how does a paper lose its EPE?

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  • $\begingroup$ I think paper has very less elastic limit that's why it will stay rolled up $\endgroup$ – Sourabh Sep 29 '18 at 18:33
  • $\begingroup$ I have limited knowledge on EPE... elastic limit? $\endgroup$ – yolo Sep 29 '18 at 18:36
  • $\begingroup$ Elastic limit is the maximum strain produced in body from where if unloaded it will regain its orignal configuration $\endgroup$ – Sourabh Sep 29 '18 at 18:39
  • $\begingroup$ But having a low elastic limit doesn't answer how the energy gets released $\endgroup$ – yolo Sep 29 '18 at 18:42
  • $\begingroup$ Yes , that's why i had not answered just commented $\endgroup$ – Sourabh Sep 29 '18 at 18:43
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paper is subject to creep: when an external load is applied, the resulting internal stresses relax slowly over time and the paper takes a set, meaning its original shape is deformed. The set persists even when the external load is removed.

That deformation happens because under steady stress, the paper fibers slowly slip past one another and the deformation stresses diminish in response.

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  • $\begingroup$ what about the EPE. Your just summing up the concept of rolling paper and it unravelling in one word $\endgroup$ – yolo Sep 29 '18 at 20:21
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    $\begingroup$ look up the mechanism of creep. $\endgroup$ – niels nielsen Sep 29 '18 at 20:23
  • $\begingroup$ @nielsnielsen You might improve your answer with a link to it $\endgroup$ – Bergi Sep 29 '18 at 21:37
  • $\begingroup$ will edit answer instead, thanks for the suggestion $\endgroup$ – niels nielsen Sep 30 '18 at 1:19
  • $\begingroup$ It should be noted that moisture greatly increases creep in paper. $\endgroup$ – Hot Licks Sep 30 '18 at 1:56

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