Verfahren zum Herbeifuehren und Steuern eines Schaeumvorgangs unter der Einwirkung von Induktionswaerme

摘要

1312729 Magnetic foams W C HELLER JNR 23 Nov 1970 [8 Dec 1969] 55601/70 Heading H1H [Also in Division C3] An article expandable upon exposure to the magnetic field of an induction heating coil comprises a composition foamable upon the application of heat thereto, the composition having uniformly dispersed throughout, finely divided susceptor particles productive of heat when subjected to an alternating magnetic field, the particles being present in quantities sufficient to heat the composition to a foamable condition. The susceptor particles may be formed from a ferro-magnetic metal, e.g. iron, copper or aluminium, and/or alloy or from electrically non-conductive metal oxides having ferromagnetic properties; the particles used in the example being magnetic iron oxide, ferrites, magnetic cobalt steels or magnetic chromium oxide. The foamable composition in the example is polystyrene containing petroleum ether.