Praise be to Allah.
A divorce (talaaq) in writing counts as such if the husband intends divorce
If the man writes a divorce for his wife with the intention of divorce, then the divorce counts as such. If he did not intend divorce, then it does not count as such, because writing comes under the heading of a metaphor, and does not come under the heading of a clear statement of divorce.
But if he did not write the words of divorce, rather he signed a paper on which divorce is mentioned, then there is a difference of scholarly opinion concerning that: does it not count at all, or does it depend on his intention?
For more details on that, please see the answer to question no. 125215 .
Signing a divorce on more than one paper
If we say that signing is like writing, and it depends whether the husband actually intended divorce, then if he signs more than one paper and intends divorce when he signs the first paper, then he wants to confirm it with his signature on the second and third papers, or he does not intend anything [when signing the second and third papers], this only counts as one talaaq.
But if he intends divorce when signing each paper, then it counts as three talaaqs according to the majority of scholars, and she becomes irrevocably divorced from him.
Some of the scholars are of the view that it only counts as one talaaq, and that no second or third talaaq can occur except after taking the wife back or doing a new marriage contract. This is the view of Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him), and it is the view that we follow on our website.
Based on that, if we assume that you intended divorce when you signed each paper, it only counts as one talaaq, and you may take your wife back if her ‘iddah has not yet ended, otherwise you must do a new marriage contract, fulfilling the necessary conditions, namely the presence of her guardian, two witnesses and the consent of the wife, and you must give her a new mahr.
And Allah knows best.