Banbury mixer

Definition

A batch-type internal-mixing machine, named after its inventor, that has been widely used in the rubber industry since 1920 for high-volume production. It will also accept plastic molding powders. Its chief feature is an enclosed, barrel-shaped chamber in which two rotors with oppositely curved contours rotate rapidly on a horizontal axis, first masticating the rubber and then efficiently incorporating the dry ingredients. Both steam and water jacketing are provided. Batches may be up to 1000 lb. A plunger at the entrance port rides on top of the batch to furnish enough pressure for proper mixing. A hydraulically operated discharge gate is located below the mixing chamber.