Abstract: Apparatus for melting and heating shortening includes a housing having a top, a bottom and sidewalls; a heating grid mounted in the housing and spaced above the bottom thereof for melting shortening and allowing melted shortening to pass therethrough toward the bottom of the housing. A door is mounted to the housing for introducing a block of shortening onto the heating grid. A bottom heater is mounted adjacent the housing bottom for maintaining the melted shortening at a desired temperature. A control circuit maintains control of the operation of both the heating grid and the bottom heater in a predetermined fashion for initially melting a block of shortening introduced onto the heating grid while substantially preventing smoking of the same, and for maintaining melted shortening at the desired temperature.

Abstract: An ohmically or electrothermally controlled valve gate for injection molding apparatus comprises three concentrically located tubes in intimate contact with each other. The innermost tube is an electrode and also serves as the passage for flowing molding material. The outermost of the three tubes is also an electrode. The intermediate tube is a resistive heating element comprising a mixture of at least two highly compacted powders. One powder is an electrical conductor, while the other powder, which serves as a binder for the first powder, is an electrical insulator but a good thermal conductor. Current flow between the electrodes occurs at points of contact between adjacent particles of the conductive powder. Thus, the electrical resistance and therefore the generation of heat is controlled by the composition and quantity of binder in the heating element. The generated heat is conducted through the inner electrode tube to the flowing plastic to melt the plastic and "open" the gate.

Abstract: A heater has two, hollow, half-cylindrical heat guides fastened to each other at one side by an articulated connector and at the other side by a bolted joint. Internal surfaces of the heat guides represent the shape of the object being heated. On external surfaces of the heat guides, there are a series of, preferably flat splines. Lamellar heating elements are fastened to the splines. Mutual adherence surfaces of the heating elements and splines are shaped according to geometrical patterns, the appropriate selection of which changes the thermal characteristics of the heater over a wide range. The heater may be supplied from single- or three-phase mains. The heater is applicable especially for heating the cylinders, nozzles and tools of injection moulding and extrusion machines.

Abstract: For liquefying hot melt adhesive, a hopper is provided at its lower region with one or more discrete upwards projections (for example a single, fluted cone), with means for heating the projection(s). In use, a unitary mass of hot melt adhesive is lowered into the hopper to become supported on the projection(s), as a result of which the unitary mass is progressively melted and the melted adhesive flows from the bottom of the hopper.

Abstract: A method of making a magnetic recording medium including a step of continuously depositing a ferromagnetic layer with the use of electron beam for heating an evaporation source material. A container for retaining said source material in a heating position is made of a ceramics having a composition comprising 97 to 99 wt % of MgO, 0.2 to 0.5 wt % of Al.sub.2 O.sub.3 and 0.4 to 1 wt % of SiO.sub.2.

Abstract: A Joule effect electric furnace for goldsmith, dental and the like melting processes comprises a graphite crucible which constitutes by itself an electric resistance element suitable for the Joule effect heating and is connected to an electric power supply.

Abstract: An electrically heated furnace assembly, suitable for a hot isostatic press, having windings of one or more resistance heating elements, helically wound about the longitudinal axis of the furnace assembly; rigid insulating sleeves, enclosing the heating elements and substantially covering their surfaces; the insulating sleeves abutting against the leading and trailing edges of one another and against the outer, upper and lower surfaces of one another; and a spiral shelf provided about the longitudinal axis of the furnace assembly, underlying the heating elements, and abutting against the outer lower surfaces of the insulating sleeves which enclose the lowermost winding of the resistance heating elements.