The Collaborative International Dictionary of English v.0.48:

Vulcanizer \Vul"can*i`zer\, n.
   One who, or that which, vulcanizes; esp., an apparatus for
   vulcanizing caoutchouc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

vulcanizer
    n 1: someone who vulcanizes rubber to improve its strength and
         resiliency [syn: vulcanizer, vulcaniser]