DE1540482A1 - Process for insulating thin electrical conductors, in particular extremely thin copper conductors, with thermoplastics - Google Patents

Description

SfIMINS

SIEMENS-SCHUCKERTWERKE AKTIENGESELLSCHAFT

Bariin and Erlangen
Patent and license assignment

I Pr. Expl.

Φ BERLIN-8l € MEN8STA0T 7 JULY 2, 1965

65/0116

Method for insulating thin electrical conductors, in particular extremely thin copper conductors, with thermoplastic Plastics

2usat2 zuQ patent. ... ... (note S 87 492 Vl / Si,

t FLA 63/0164)

The subject of the main patent is a method for insulation Thin electrical conductor, especially thin copper conductor, as used, for example, as communication cable cores in local networks, with thermoplastic plastics, preferably with polyolefins, by immersing the conductor in a

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S09881 / 0546

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9/820/4642

thixotropic dispersion, the viscosity of which at the point of exit of the conductor is mechanically lowered, whereupon the one with a The conductor is covered with a thermoplastic material passes through one or more heated 'ifen in which the dioperaion drug evaporates while that on the ladder remaining powder sinters and fuses to form a homogeneous coating. This coating process is particularly suitable for Unigeben electrical conductors with a thin, but nevertheless sentric, polyethylene coating. Blessings on the known Method of insulating conductors with polyethylene using Hot solutions, this process has the advantage that the use of expensive solvents and the difficulties when eliminating the fumes that occur during production, there is no need. In addition, in the method according to The thixotropic dispersions used in the main patent are storage-stable and can be applied at room temperature.

The method according to the main patent is mainly used when the loolier coating to be applied to the conductor is to be thin and yet centric, as is a necessary condition, for example, in the manufacture of local cable cores. According to the main patent, insulation wall thicknesses can be applied to thin conductors, for example 0.3 mm copper conductors, which can only be produced centrically with tendon presses of such a thin wall thickness with great effort .

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BATH ORIGINAL

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To improve the quality of insulation resulting from the thixotropic Dispersion is applied to a conductor, the viscosity of which is reduced at the exit point of the conductor, therefore, according to the invention, the insulation is applied in two, at most three, passes through the dispersion. The invention provides that the initially bare conductor passes through a dispersion and the subsequent drying zone twice or at most three times. This is done by the viscosity the plastic thixotropic dispersion in one of the number of runs corresponding I-laßc reduced.

In itself, the application of an insulating layer is in several ways ■ EurchiäU'fen, known from the manufacture of the lacquer wire * application a wire enamel on copper conductor is namely in several successive passes, for example

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m six to seven or πΐ3ίιϊΓ> performed. This relatively high number of consecutive passes is therefore necessary when painting wires, because the. Application of a wire enamel in one pass

achievable wall thickness, for example with 0.3 copper conductor, in of the order of about 10 to 15 / u »

In contrast, one with the process according to the main patent, in which the ..Lleiter passes through a thixotropic dispersion, whose Viscosity at the exit point of the conductor decreased the required insulation wall thickness is easily possible

09881/0546

BATH ORIGINAL

PLA 9/820/4642

for example in the order of 100 / rev in one pass to apply to a 0.3 ram copper conductor. The invention is based on the knowledge that it is still cheaper, the needed Insulation wall thickness not in one pass, but in two, to apply a maximum of three passes on the ladder.

When isolating a 0.3 mm copper conductor with 100 / u insulation wall thickness is therefore in the implementation of the inventive concept the insulation is applied in two layers with a wall thickness of 50 / U each. The smaller wall thickness for a Passage of the conductor through the dispersion is made by a corresponding Dilution of the dispersion achieved. Compared to the ira main patent specified structure of a suitable polyethylene

z. B. dispersion is the proportion of water and / or methyl alcohol increased to such an extent over the other constituents of the dispersion that an order of 50 / u in results in one pass. "It is essential here, however, that too the thixotropy of the dispersion is retained when the dilution is carried out. Despite the dilution, the dispersion must be Exit of the conductor from the application device taken along will. So it must not slip off the ladder. It must be taken into account that, for example, a polyethylene dispersion despite the added wetting agent does not contain any polar groups, as is the case, for example, with a Laek resin of the Pail.

By applying the insulation in two or even three Running through, as the invention, provides, it is achieved that *

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The insulation resistance of the finished insulation is considerably higher is alo for insulation that is applied in one pass became. Versue he have shown that in carrying out the goddamn invention Insulation produced in two passes, stored in water, has a substantial insulation resistance maintained for a longer time than is the case with the veins of the fall the insulation of which was applied in one pass.

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2 claims

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BATH

Claims (2)

Claims 1. A method for insulating thin electrical conductors, in particular extremely thin copper conductors, with thermoplastics, preferably with polyolefins, in particular with polyethylene, by immersing the conductor in a thixotropic dispersion of the thermoplastic material, the viscosity of which is mechanically reduced at the exit point of the conductor, whereupon the conductor provided with a coating of a thermoplastic material passes through one or more heated ovens in which the dispersant evaporates while the powder "remaining on the conductor" sinters and ^{fuses to form a homogeneous M} coating, according to the patent (Note S 87 492 VIIId / 21c -? LA 63/0164), marked thereby, that the insulation is applied to the conductor in two or at most three passes. 2. The method according to claim 1, characterized in that the viscosity of the thixotropic dispersion corresponds to the number of Runs is degraded. : - 6 909Ö81 / 05A6