"I"

Insert - A part, usually metal, which is placed in a mold and appears as an integral part of the molded product.

Internal Mixer - An enclosed mixing machine for rubber or other suitable material, inside or which are two (2) heavy mixing rotors which revolve in opposite directions with a small clearance between themselves and tine enclosing walls. The mixing chamber is jacketed or otherwise arranged for water-cooling, and is provided with a feeding hopper which can be closed by means of a pneumatically operated, vertical ram. Leading examples are the Banbury, the Boiling and the Shaw mixers.

IRHD (International Rubber Hardness) - For complete definition see ASTM D 1415-68 Standard Method of Test for International Hardness of Vulcanized Natural And Synthetic Rubbers.

Isolators - A term used to describe a bearing seal - which replcases an oil seal providing more reliable sealing.