In reference to the patent: USD234017
Who owns the rights to plastic spoons now? Their patent was only to last 14 years
'Ask Patents' user has already answered a similar question Expiry date of patent no 6676109 but in your specific case you'll need to apply that answer as follows:
US MPEP 2701 Patent Term [R-11.2013] states that..
Design patents have a term of fourteen years from the date of patent grant, except for any design patent issued from applications filed on or after the date of entry into force of the Hague Treaty as to the United States, has a term of fifteen years from the date of patent grant (see Pub. L. No. 112-211). See 35 U.S.C. 173 and MPEP § 1505.
above goes with duly payment of maintenance fee and subject to any invalidation or re-examination proceeding. if all above are full filled then a design patent to last 14 years after the expiry of said term patent will be in public domain.