Polymer composition for electric devices
FIELD: manufacturing technology.
SUBSTANCE: invention relates to a cable, including a cross-linked cable, also to a method for production of a cable, more preferably, to production of a power cable. Cable includes a conductor enveloped by one or more layers, wherein at least one of the above said layers is made from a polymer composition, which contains polyolefin and an anion-exchange additive of hydrotalcite type in the amount from 0.000001 to less than 1 wt% with respect to the total weight of the polymer composition. Herewith polyolefin is an unsaturated polymer of ethylene of low density, which is selected from an unsaturated ethylene homopolymer of low density or an unsaturated ethylene copolymer of low density and one or more comonomers in an amount of at least 50 wt% with respect to the total weight of the polymer component(s) present in the polymer composition. Besides, the polymer composition, if necessary, additionally contains peroxide in the amount of less than 35 mmol -O-O-/kg of the polymer composition. Herewith the cable, probably, is ligated and then cross-linked.
EFFECT: obtained cable has low conductivity and good mechanical properties.
17 cl, 1 dwg, 2 tbl
SUBSTANCE: electrically insulating material for a high-voltage rotary machine consists of a base resin and powdered filler distributed in the base resin as the only filler, which is formed by plate-like aluminium oxide particles, wherein the powdered filler consists of particles with size of 0.002-150 mcm and volume ratio thereof ranges from 50% to 75%, preferably about 70%. The insulating paper for a high-voltage rotary machine contains said electrically insulating material. The insulating tape for a high-voltage rotary machine includes a carrier tape and an insulation paper tape, wherein the insulation paper tape is placed and attached onto the carrier tape.
EFFECT: improved electrically insulating material.
SUBSTANCE: coating includes following components, wt %: dispersed silica 75-89; magnesium oxide 10-20; colloid silica 1-3.
EFFECT: high electric resistance and maintaining magnetic properties of steel at acceptable level due to elimination of zone enriched with non-metallic inclusions in under-surface layers.
2 dwg, 2 tbl
SUBSTANCE: non-insulated wire of valve metal is wound to a frame or the core; insulation layer is formed in process of winding by microarc oxidizing. Winding is performed in a bath with electrolyte with a metal tube submerged to it. During winding the wire is drawn through the tube. The process is performed using two alternate current sources. The tube and wire are connected to different poles of the first current source; one pole of the other current source is also connected to the wire while its other end is connected to the bath case. Inner diameter of the tube is selected from the formula dtube=dwire+(2…30) mm, where dwire. At the end of winding process at fixed voltage current is measured in the circuit of the second source and quality of the produced insulation is assessed against measurement results.
EFFECT: improving quality.
3 cl, 1 dwg
SUBSTANCE: method involves application of an adhesive layer based on a thermoplastic adhesive and further application of a functional layer from nanostructured polymer composite material based on polyethylene with disperse filler from montmorillonite. The adhesive layer is applied by wire drawing through molten thermoplastic adhesive. The functional layer is applied by extrusion.
EFFECT: invention allows increasing physical and mechanical and operating characteristics of the coating and simplifying a procedure for obtaining a coating.
9 cl, 2 dwg, 1 ex
SUBSTANCE: invention refers to a manufacturing method of an insulated electric conductor and to a device used for manufacture of insulated electric conductor, which can permanently manufacture the conductor having large shaped width in compliance with the required dimensions in comparison to rolling, where conductor is rolled with a pair of freely rotating rolls, and which will allow combined performance of all processes.
EFFECT: possibility of combined performance of all manufacturing processes of an insulated conductor.
4 cl, 8 dwg
SUBSTANCE: method involves arrangement of metallic workpiece in glass tube, melting of metallic workpiece together with tube, drawing of metallic molten metal in the form of metallic wire coated with layer of glass, cooling so that wire from amorphous alloy and coated with glass layer is obtained, and removal of glass layer from wire surface. Glass layer is removed by wire drawing along curved surface of solid body across the generatrix of curved surface with curvature radius providing the tensile stress in glass layer, which is equal to or more than its ultimate strength at tension and tensile stress in wire at bending when it is drawn across the generatrix of curved surface of solid body at the interval of the ultimate strength of glass at tension and flexibility limit of amorphous alloy of wire.
EFFECT: increasing ductility, ultimate strength, degree of homogeneity of magnetic properties throughout the length of amorphous wire, and increasing degree of magnetisation.
6 cl, 10 dwg, 1 ex
SUBSTANCE: procedure consists in reducing weight (volume) of main drop and in introducing additional glass tube with metal core inside as metering material. To melt the metering metal core an additional inducer above the main high frequency inducer is introduced into an installation for micro-wires casting.
EFFECT: production of specifically thin cast micro-wires with diametre from 0,5 to 3 mcm with stable chemical composition.
FIELD: electrical engineering; using silanol cross-linked polyethylene covered wires or cables.
SUBSTANCE: proposed method includes covering of cable or wire conductor with silanol cross-linked polyethylene insulation followed by cooling down wires or cables and placing them in horizontal branches into water-filled basket. After that either current is passed through cable or wire thereby heating it to temperature not over maximal admissible value ensuring insulation resistance to thermal deformation and exposing it to this temperature for period required for silanol cross-linking of polyethylene, or basket is placed in heated tank filled with water, steam, or steam-water mixture, and held in this tank at mentioned temperature for time required for polyethylene cross-linking, or water is drained from basket and then the latter is placed in heated tank filled with water, steam, or steam-water mixture and held in this tank at mentioned temperature for time required to ensure silanol cross-linking of polyethylene.
EFFECT: enhanced quality of insulation, reduced cost, time, and heat energy requirement.
SUBSTANCE: invention relates to a multimodal polyethylene resin, an extrusion composition, containing it, and products, which can be used for manufacturing extrusion coatings, extrusion profiles and films.
EFFECT: extrusion composition contains the multimodal polyethylene resin and from 2 to 20 wt % of a polyethylene low density resin, and is characterised by high rates of a technological line, high resistance to resonance in the process of the extrudate drawing and essentially reduced degree of necking.
9 cl, 5 dwg, 10 tbl, 11 ex
SUBSTANCE: group of inventions relates to polyethylene compositions for films or cast products. Composition has melt fluidity index at 5 kg/190°C (MI5 kg) from 0.25 to 3 g/10 min, Mz higher than 2000000 g/mol and lower than 370000 g/mol and Hostalen index (HI) value from 0.18 to 18. When melt fluidity index at 5 kg/190°C (MI5 kg) is higher than 1.9 g/10 min, Hostalen index (HI) value is higher than 1.
EFFECT: polyethylene composition in accordance with invention, possessing specified molecular-weight distribution and long-chained branched structure, possesses improved technological properties, and obtained films have higher mechanical impact strength with film thickness being 10 mcm than at 20 mcm, in accordance with measurement of dart drop impact (DDI).
9 cl, 4 tbl, 8 ex, 1 dwg