Mill 4 : A machine consisting of two adjacent metal rolls, set horizontally, which revolve in opposite directions (e.g., toward each other as viewed from above) used for the mechanical working of rubber and plastics compounds
Environmental Health and Safety, Glossary, University of Chicago, Illinois, USA 2010. http://safety.uchicago.edu/tools/glossary.shtml, (Ergo - Amer) {753}