Abstract: A method for the production of closed edge filters suitable for filtering molten metal and filters made by such a method. The method comprises: providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter; applying a liquid comprising an organic coating component to the first surface; solidifying the organic coating component to form a filter precursor having a volatilizable coating on the first surface; impregnating the filter precursor with a slurry comprising particles of a refractory material, a binder and a liquid carrier; and drying and firing the impregnated filter precursor to form the filter having a closed edge.

Abstract: A method for the production of closed edge filters suitable for filtering molten metal and filters made by such a method. The method comprises: providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter; applying a liquid comprising an organic coating component to the first surface; solidifying the organic coating component to form a filter precursor having a volatilisable coating on the first surface; impregnating the filter precursor with a slurry comprising particles of a refractory material, a binder and a liquid carrier; and drying and firing the impregnated filter precursor to form the filter having a closed edge.

Abstract: Method for the production of a closed edge refractory foam filter, by providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter, applying a liquid including an organic coating component to the first surface, solidifying the organic coating component to form a filter precursor having a continuous volatilizable coating on the first surface, and impregnating the filter precursor with a slurry containing particles of a refractory material, a binder and a liquid carrier. The impregnated filter precursor is dried and fired to form the filter having a closed edge.

Abstract: A method for the production of closed edge filters suitable for filtering molten metal and filters made by such a method. The method, comprises: providing a reticulated foam substrate having at least one first surface for forming a side face of the filter and two opposed second surfaces for forming the through-flow faces of the filter; applying a liquid comprising an organic coating component to the first surface; solidifying the organic coating component to form a filter precursor having a volatilisable coating on the first surface; impregnating the filter precursor with a slurry comprising particles of a refractory material, a binder and a liquid carrier; and drying and firing the impregnated filter precursor to form the filter having a closed edge.

Abstract: The opening cylinder comprising a cylindrical ring serving as a needle support and being provided with needle-housing bores extending from the inner ring surface to the outer one is designed to carry needles comprising a point section of generally tapered shape and a shaft section, the latter being pressed into and seated with force fit in a radially inner section of a corresponding one of said bores. A radially outer section of the bore surrounds a portion of said needle point section so as to form an annular groove therearound at the orifice of the bore in the outer ring surface. The radially inner section of the bore or at least part thereof has a diameter which is at least as great as the diameter of the outer section of the bore in the range of its orifice in the outer ring surface.