Abstract: A device including, and a method for producing, an electric insulator made of plastic, the insulator having a centrally arranged core made of glass fiber reinforced plastic, and having a plurality of insulation screens arranged coaxially around the core in an offset manner in an axial direction of the core. The method steps include: positioning a casting mold in an axial position around a vertically arranged core; producing a sealing connection between the core and the casting mold; injecting a liquid plastic material under pressure into an axial area of the casting mold; curing the liquid plastic material in the casting mold, thereby creating an insulation screen; deactivating the sealing connection; displacing the casting mold axially in a downward direction along a defined displacement path; and repeating the above steps until an insulator is produced having a desired number of insulation screens.

Abstract: The invention relates to a method and a device for producing an electric insulator (1) made of plastic comprising a central hollow core (2) in addition to a plurality of insulating screens (3) which are arranged in a coaxial manner around the hollow core (2) and which are disposed in the axial direction of said hollow core (2).

Abstract: An extrusion process for the manufacture of insulated winding wires. Part crystalline thermoplastic polycondensates with crystallite melting points above 170.degree. C., preferably above 250.degree. C., are extruded. Polyethylene terephthalate is the polycondensate of choice. These are filled with 5-15% by weight titanium dioxide. The result is the avoidance of fissure formation.

Abstract: A method of insulating an electrical conductor by applying thereto a coating of a polyesterimide resin which can be hardened through its free OH groups from a resin melt at above 100.degree. C., wherein the resin used is solvent-free and has been prepared by esterification or ester-exchange of starting materials for the polyesterimide in the presence of an excess of one or more short-chain diols and subsequent removal of the diol or diols in such a way that the condensation is only effected to an extent such that the Durrans softening point of the unhardened resin is not above 150.degree. C. (preferably not above 100.degree. C.) and the viscosity of the molten resin at 180.degree. C. is not above 5000 (preferably not above 1000) mPa s (cP). This process avoids the disadvantages encountered when a solvent is present in the insulating bath.

Abstract: A partially crystalline thermoplastic polyamide for use in the preparation of insulated wires through the extrusion of a thermoplastic coating, consisting of terephthalic acid or a functional derivative thereof, hexamethylenediamine and isophoronediamine; also disclosed are a process for the preparation of insulated wires using the above polyamine; and an insulated wire employing such polyamide as the thermoplastic coating.

Abstract: An aqueous electrically insulating varnish is provided along with a process for producing the varnish; the process comprises the steps of reacting cyclopentane tetracarboxylic acid with dicyclic, diprimary aromatic diamine in the presence of water and neutralizing the condensation product to form a varnish.

Abstract: A process for providing electrical conductors with a heat resistant, insulating coating of resin. The process comprises passing the conductors through a melt of a resin which is polyester curable through free hydroxy groups, having crosslinking equivalent weight of 400-1600, which is produced by condensation at a temperature corresponding at least to the temperature of the melt to an extent such that no substantial further condensation takes place in the melt.

Abstract: A method of extruding a thin sheath of plastic material about electric wire, utilizing a plastic material capable of being shaped by extrusion after having been heated in a screw extruder, this material exhibiting the technical characteristics required for enamel-type insulation after cooling, without necessitating subsequent treatment. An extrusion material containing at least one partially crystalline thermoplastic polycondensate wherein the crystallites have a melting-point above 170.degree. C. answers these requirements.

Abstract: A varnish is provided for coating a wire which is directly tinnable. The varnish comprises hardenable polyester urethane having a urethane equivalent weight of 150-850, the polyester being formed as the product of the reaction of a saturated polyester containing at least two hydroxyl functional groups and an aromatic isocyanate containing at least two functional groups of isocyanate and a phenol-free solvent for the polyester urethane. A process for producing this varnish is also provided.

Abstract: Water dilutable electroinsulation enamels are made by reacting a hydroxyl group containing polyesteramide of low acid number with at least one amine in an amount of 5 to 30% by weight relative to the weight of the ester imide whereupon the reaction product is diluted with water until it has the desired viscosity for lacquering purposes.