SU528045A3 - Method for continuous manufacture of multilayer coating - Google Patents

Description

one

The invention relates to the technology of making electrical cables with a multilayer coating of polymeric materials, in particular, the application of a multilayer coating by extruding it onto a continuous movement of the core of a cable product with the combined heat treatment of the medium under pressure, for example, heating, in order to cure or cooling and hardening. At the same time, the coating material of one or several layers may contain additives that give it electrically conductive properties.

Methods are known for the continuous manufacture of a multilayer coating of a cable product on a press, to the outlet of the head of which a chamber with pressurized medium is sealed, based on forming the said coating in the head, overlaying it on the core through the head and the chamber with said medium and processing, for example, the vulcanization of a coating in this medium.

According to the proposed method, in order to improve the quality of the coating, an additional medium, preferably dry, is introduced into the gap between the coating layers in the overlap area of the core.

an inert gas, and maintain it under a pressure less than the pressure of the medium in said chamber.

FIG. 1 shows a setup diagram of a reagent method proposed in a general form; in fig. 2 is a diagram of the extrusion machine head entering the unit in a section; in fig. 3 is a diagram of the pressure differential control system used in one embodiment of an installation implementing the proposed method.

The bare solid aluminum wire of the I sector cross-section, on which the extra multilayer coating is applied, from the drum 2 by means of the pushing track 3 is directed into the head of the extrusion machine 4, where the application of the multilayer coating is performed. Then, a wire with a multilayer coating applied onto it goes directly into the inclined chamber of vulcanisation 5, filled with steam at superatmospheric pressure and water (at its lower end) for cooling at the same pressure and hermetically connected to the output end of the blower, and from there the wire goes to a cooling bath not shown in the drawing, and

The receiving drum 6 is equipped with a 1THE-DRIVE Caterpillar adapter 7.

The head 8 of the extrusion machine 4 has an extrusion hole on the output end of the extruder formed by the external mouthpiece 9 and the internal mouthpiece 10 of the mandrel. Two intermediate mouthpieces 11 and 12 are located between the outer 9 and the inner 1.0 socket, and the intermediate mouthpiece 11, located closer to the outer mouthpiece 9, stands for the hole JQ formed by the outer mouthpiece 9 and the intermediate mouthpiece 12, between the mouthpiece 12 and the channel 13.

The plastic in the plastic state is fed through the channel 14 into the annular space, 5 bounded by intermediate mouthpieces 11 and 12, and the semiconductor polyethylene in the plastic state is fed through the channel 15 into the ring-shaped spaces between the internal mouthpiece 10 and the multi-sided mouth of the head and the other. 11 and the mouthpiece 9.

When applying a multilayer coating on wire 1, the inner semiconductor semiconductor polyethylene layer 16 is extruded directly onto 25 conductor 1 due to extrusion pressure, and the intermediate polyethylene layer 17 and hemispherical layer 18 are extruded to form full and durable contact 5 between the layers behind the extrusion hole , formed by an external mouthpiece 9 and intermediate 12, thus creating a multi-layer coating. Nitrogen under pressure is injected through channel 19 into the space 20 between the semiconductor layer 16 and the coating of layers 17 and 18 and supports it under pressure that is less than the vapor pressure in chamber 5 so large that the pressure drop across the thickness of the extruded composite coating from The layers 17 and 18 in the zone of the extrusion orifice are sufficient to force this combi-coated coating to firmly settle on the wire 1 covered with the first layer, but it is enough to put 1m in thickness in order to press the combined coating called q in the extrusion otverstie.45

A combined coating containing an inner semiconducting polyethylene layer 16 J with a radial thickness of 0.5 mm, an intermediate polyethylene layer 17, 0.8 mm thick, 50 outer semi-conductive / polyethylene layer 18. 0.5 mm thick, may be applied to the metal core of the sector section 15 mm.

In the event that the pressure of the water vapor in S5 measure 5 is within 13.35 - 14.75 atm, the difference C in the thickness of the extruded combined coating of layers 17 and 18 is extruded to be approximately 0.7. -2.0 atm.50

In another embodiment, the nitrogen is also injected into the tube of the mandrel, which is provided with a fluid-tight seal (not shown in the drawing) on the left flank of the tube along which the heart moves. Nitrogen pressure in the mandrel tube; maintained within 5-10 atm, which is sufficient to provide the required nitrogen pressure B, the space 20 on the semiconducting polyethylene layer 16 and so that the layer 16 does not squeeze back along the mandrel tube.

The image in FIG. 3, the differential pressure control system is designed to maintain a constant pressure differential across the thickness of the extruded combination coating of the layers 17 and 18 as it appears at the exit of the extrusion opening of the extrusion machine 4. This system includes a differential pressure sensor 21 connected to the chamber of the vulcanisation 5 and the canal 19 passing through the intermediate mouthpiece 12. On the other hand, the sensor 21 is connected to the regulator 22, and the vacuum pump 23 is connected through the regulator 22 through the pipe 24 interstitial muvdshtuke 12. Volume 25 is also nitrogen Cpd yen through the regulator 22 through the tube 24 with Kapal 19. The steam under superatmospheric dav.penii introduced into chamber 5 through inlet tube.

During installation, the sensor 21 transmits to the regulator 22 through a transducer (which is not shown in Fig. 3) a signal proportional to the pressure difference across the tholeedine of the extruded combined coating at the extrusion hole. This signal is compared with the level of pressure drop previously set in controller 22, and in accordance with the difference between this signal and the level of the previously established pressure difference automatically closes, valve 1 is opened (not shown in the drawing), nitrogen is admitted or released through tube 24, respectively into or out of channel 19, and the regul / shru thus operating the vacuum pump 23.

Claims (1)

Claim method of continuous fabrication of a multi-layer coating of a core, for example, a cable product on a press, to the outlet of the head of which a chamber with a medium under pressure is hermetically attached, based on the shape of the coating in the head, laying it on the core pulled through a head with a chamber, and processing, for example vulcanization, of the coating in said medium, characterized in that in order to ensure the quality of the coating, between the coating layers in the zone Proposition them serdechsh1k introduced additional medium preimuojecTBCHHO dry inert gas and maintained at a pressure less PRESSURE} br s CDS at specified second chamber. CHCHCHCHCHCHCHCHChChChH of w. one Fig.z