Is chips a proper noun or a common noun?

The noun 'chips' is a common noun, a Word for any chips of any kind.

A proper noun is the name of a specific person, place, thing, or a title; for example:

Dr. John D. Chips DDS, Gibsonia, PA Chips Drive, Killeen, TX or Chips Road, Newport, NC Chips Ahoy cookies (a Nabisco brand) "Goodbye Mr. Chips" by James Hilton; 1939 movie with John Donat and Greer Garson