Mich. Comp. Laws § 445.614

Sec. 4. If a customer does not claim possession of the die, mold, or form within 120 days after the date the molder receives the return receipt of the notice sent pursuant to section 3, or does not make other arrangements with the molder for storage of the die, mold, or form within the time limit set forth in this section, all rights, title, and interest of the customer in the die, mold, or form shall be transferred by operation of law to the molder for purposes of destroying the die, mold, or form. This section shall not be construed to affect a right of a customer under federal patent or copyright law, or any state or federal law pertaining to unfair competition.