Abstract: A packing yarn and a method of manufacturing a packing yarn utilize at least two bands that are at most 5 mm wide and are joined together by a yarn manufacturing method. The bands are formed of a laminate having at least one layer of flexible graphite foil and at least one layer of a plastic foil with a tensile strength of at least 25 MPa and an elastic modulus of at least 0.4 GPa. The layers of graphite foil and plastic foil are joined by adhesive bonding, by a non-adhesive-like coupling agent or by welding. The bands are produced from the laminates by cutting, which is preferably effected continuously.

Abstract: A process for the preparation of a laminate of at least one metal layer and at least one layer of flexible graphite includes producing a non-detachable bond between the graphite and the metal without using a mechanical anchoring device and without using a known adhesive. Initially, a contact surface-active agent from the group including organosilicon compounds, perfluorinated compounds and metal soaps is applied in a thin layer to at least one of the surfaces to be bonded. Then the surfaces to be bonded are brought into contact and bonded together by the action of pressure and heat.

Abstract: Flexible graphite layer material containing at least one metal moylbdate with a solubility in water of 10.sup.-2 to 10.sup.-4 g/100 ml to inhibit corrosion. The corrosion inhibitor may be incorporated by first immersing the graphite layer material in a solution of an alkali metal molybdate, drying, and then immersing in a solution of very soluble metal salt in which the metal when combined with molybdate to form metal molybdate has the defined solubility. The graphite layer material is then dried and contains the desired molybdate corrosion inhibitor.

Abstract: A flexible graphite laminate produced by compacting expanded graphite having incorporated an alkali metal salt containing at least one of the elements chromium, molybdenum and tungsten. The alkali metal salt reduces the corrosive properties of the flexible graphite laminate. The alkali metal salt may be incorporated during or after manufacture of the flexible graphite laminate from graphite.

Abstract: Production of graphite-hydrogensulfate by dispersing crystalline graphite particles in sulfuric acid, agitating the mixture, adding hydrogen peroxide to the agitated dispersion and continuing agitation until the graphite is converted to graphite-hydrogensulfate. Excess acid is separated and the residual acid in the solid product is removed by washing. The graphite-hydrogensulfate may be heated to transform it into expanded graphite. The method minimizes pollution of the atmosphere with noxious gases and also makes possible ready recovery of unused acid.