Packing Rings, Method for Production of the Packing Rings, and Seal Device Using the Packing Rings

摘要

A packing ring (2) is characterised by comprising: a packing (3) obtained by spirally winding a ribbon of expanded graphite into a roll and compression moulding said roll; and an annular mass (4) of superposed sheets of expanded graphite incorporated into said packing (3) by compression moulding so as to give rise to a composite structure having at least one packed part (10) of increased density in at least one of an inner peripheral part and an outer peripheral part of said packing.