Jacket - A tough sheath to protect an insulated wire or cable, or to permanently group two or more insulated wires or cables.

Jet Molding - Processing technique characterized by the fact that most of the heat is applied to the material as it passes through the nozzle or jet, rather than in a heating cylinder as is done in conventional processes.

Jetting - Turbulent flow of resin from an undersize gate or thin section into a thicker mold section, as opposed to laminar flow of material progressing radially from a gate to the extremities of the cavity.