EP0029234B1 - Low voltage cable provided with improved insulating layer - Google Patents

Low voltage cable provided with improved insulating layer Download PDF

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Publication number
EP0029234B1
EP0029234B1 EP80107059A EP80107059A EP0029234B1 EP 0029234 B1 EP0029234 B1 EP 0029234B1 EP 80107059 A EP80107059 A EP 80107059A EP 80107059 A EP80107059 A EP 80107059A EP 0029234 B1 EP0029234 B1 EP 0029234B1
Authority
EP
European Patent Office
Prior art keywords
parts
insulating layer
low voltage
weight
voltage cable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP80107059A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0029234A1 (en
Inventor
Germano Beretta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pirelli and C SpA
Original Assignee
Cavi Pirelli SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cavi Pirelli SpA filed Critical Cavi Pirelli SpA
Priority to AT80107059T priority Critical patent/ATE5284T1/de
Publication of EP0029234A1 publication Critical patent/EP0029234A1/en
Application granted granted Critical
Publication of EP0029234B1 publication Critical patent/EP0029234B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00—Insulated conductors or cables characterised by their form
    • H01B7/02—Disposition of insulation
    • H01B7/0208—Cables with several layers of insulating material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/44—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins
    • H01B3/443—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins from vinylhalogenides or other halogenoethylenic compounds

Definitions

  • the present invention concerns an improvement to low voltage cables wich comprise a single conductor and which are insulated with a material based on polyvinylchloride (PVC), said cables being well known as wiring cables for civil appliances.
  • PVC polyvinylchloride
  • the insulating layer of the wiring cables for civil appliances is always realized with materials having a very high mineral filler content up to 30 parts by weight per 100 parts by weight of resin.
  • the high friction coefficient due to the roughness creates difficulties during drawing, and abrasions because of the contact with the inner surface of the conduits.
  • the content of polyvinylchloride is always high with respect to said mineral filler.
  • the polyvinylchloride is a thermoplastic material and in case of overheating it melts, exposing the conductor, with serious risk of short circuits.
  • a flame-resisting electrical cable (DE ⁇ B ⁇ 2 051 192) having a conductor constituted by one wire or more wires stranded together and covered with an insulating layer and with an outer layer, both layers being made from a material based on polyvinylchloride (PVC), and containing at least a plasticizer, said material for the insulating layer containing also at least a mineral filler.
  • PVC polyvinylchloride
  • the materials forming the insulating and/or the outer layer contain from 6 to 40 percent by weight of magnesium carbonate on the total quantity of the material and at least 20 percent by weight of a chlorinated substance and from 1 to 15 percent by weight of antimony trioxide.
  • the present invention aims to improve with the electrical characteristics being the same, any other properties of the wiring cables for civil appliances used up to now, eliminating the drawbacks, but retaining very low costs of the product.
  • the said aim is accomplished by the present invention by providing a low voltage cable having a conductor constituted by one wire or more wires stranded together and covered with an insulating layer and with an outer surrounding layer, both layers being made from a material based on polyvinylchloride (PVC), and containing at least a plasticizer, said material for the insulating layer containing also at least a mineral filler, which is characterized by the fact that said mineral filler is contained in the material for the insulating layer in a proportion from 40 to 500 parts by weight per 100 parts by weight of polyvinylchloride, said plasticizer is contained in the material in a proportion from 60 to 120 parts by weight per 100 parts by weight of polyvinylchloride, said outer layer being a skin for the surface of said insulating layer and having a thickness from 5 to 30 percent of the thickness of said insulating layer, the material constituting said skin containing a quantity of plasticizer from 10 to 40 parts by weight per 100 parts by weight of polyvinylchloride.
  • the invention teaches a cable the insulating layer of which, even if it comprises a high mineral filler content, much higher than the presently used content, has such a structure as to offer good mechanical characteristics, a very low friction coefficient, and a high fire resistance. Furthermore said insulating layer can be easily stripped and therefore easily applied and permits a high reliability in case of overheating.
  • the low voltage cable 10 shown in figure 1 comprises a conductor 11 constituted by a single wire, but it is understood that said conductor 11 could also comprise a plurality of wires stranded together.
  • the conductor 11 is covered with an insulating layer 12 extruded thereon.
  • the insulating layer 12 is constituted by a material based on polyvinylchloride (PVC), containing at least a plasticizing mineral filler.
  • PVC polyvinylchloride
  • the mineral filler in the material is present in a proportion from 40 to 500 parts by weight per 100 parts by weight of polyvinylchloride (PVC).
  • the material of the insulating layer further contains a plasticizer in a proportion from 60 to 120 parts by weight per 100 parts by weight of PVC.
  • the plasticizer is contained in a quantity of 100 parts by weight per 100 parts by weight of PVC.
  • the insulating layer 12 is covered on its surface with a skin 13 or thin layer which is constituted by a material based on PVC and containing at least a plasticizer.
  • the plasticizer is Di-2-(ethylhexyl)phthalate (D.O.P.).
  • the content of plasticizer contained in the skin 13 is 10 to 40 parts by weight per 100 parts by weight of PVC. Its preferred content is 30 parts by weight per 100 parts by weight of PVC.
  • the thickness of the skin 13 is small with respect to the thickness of the insulating layer.
  • the skin thickness might be comprised between 5 and 30% of the insulating layer thickness and preferably is 15% of the same.
  • the structure of the cable 10 inclusive of skin 13 has a resistance to tensile stresses sufficient for the handling of the cable since the mechanical stresses occuring for example during the winding on the drum are taken up prevalently by the skin 13.
  • the electrical characteristics of said cable are good.
  • the outer surface of the cable 10 is moreover very smooth and very bright, owing to the prevalent presence of PVC in the skin 13, so that the cable 10 has a very low friction coefficient at its outer surface in respect to that of cables in use up to now. Said smoothness and brightness permit the drawing of the cable inside the conduits with easy, gentle and continuous sliding.
  • Another advantage offered by the cable 10 is the ease of stripping of the conductor 11, so that the insulating layer can easily and completely be removed from the conductor during the connecting and sealing operations.
  • any melting of the PVC will never expose the conductor 11, owing to the presence of a high mineral filler content which filler remains compact, preventing the melted PVC from draining and on the contrary keeping the latter in place.
  • a cable 10 according to the invention comprising an insulation with a high content of mineral filler has always a sufficiently high plasticizer-resin ratio, contributes to give the cable 10 itself a good cold flexibility.
  • a further property of cable 10 is a good behaviour to thermocompression because of the essentially "mineral" structure of the material.
  • Said structure shown by a material with high mineral filler content, improves also the thermal conductivity of the cable 10 with respect to conventional materials. It follows a more rapid cooling of the cable.
  • the material according to the invention does not include any colouring pigments, especially in the insulating layer, with a minimum risk, therefore, of decay of the insulating characteristics.
  • the presence of a high mineral filler content makes the cable 10 particularly resistant to flames since said high quantity of filler, besides being incombustible, improves the compatibility of PVC resin with chloroparaffins.
  • a cable 10 has a further advantage resulting from the good impermeability of skin 13, which lowers greatly the absorption of water of the assembly.
  • the advantage is considerable if it is considered that to draw a bundle of cables, with dimensions equal to those of the bundle on which the experimental tests have been conducted, but realized with two cables of conventional type, it is necessary to apply a drawing force of 9 kg.

Landscapes

  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Insulated Conductors (AREA)
  • Organic Insulating Materials (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Cable Accessories (AREA)
  • Communication Cables (AREA)
EP80107059A 1979-11-15 1980-11-14 Low voltage cable provided with improved insulating layer Expired EP0029234B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT80107059T ATE5284T1 (de) 1979-11-15 1980-11-14 Niederspannungskabel mit isolierschicht.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT2729579 1979-11-15
IT27295/79A IT1165372B (it) 1979-11-15 1979-11-15 Cavo per basse tensione con isolante perfezionato

Publications (2)

Publication Number Publication Date
EP0029234A1 EP0029234A1 (en) 1981-05-27
EP0029234B1 true EP0029234B1 (en) 1983-11-09

Family

ID=11221372

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80107059A Expired EP0029234B1 (en) 1979-11-15 1980-11-14 Low voltage cable provided with improved insulating layer

Country Status (13)

Country Link
EP (1) EP0029234B1 (es)
JP (1) JPS5684811A (es)
AR (1) AR221445A1 (es)
AT (1) ATE5284T1 (es)
AU (1) AU541268B2 (es)
BR (1) BR8007440A (es)
CA (1) CA1163688A (es)
DE (1) DE3065555D1 (es)
ES (1) ES8106629A1 (es)
IT (1) IT1165372B (es)
MX (1) MX152432A (es)
NO (1) NO155266C (es)
NZ (1) NZ195523A (es)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1160761B (it) * 1983-03-25 1987-03-11 Pirelli Cavi Spa Cavo per basse tensioni
GB2161644B (en) * 1984-07-09 1987-11-11 Pirelli General Plc Flexible electric cable
US8330045B2 (en) 2005-12-26 2012-12-11 Industrial Technology Research Institute Fire-resistant wire/cable
CN102197077B (zh) * 2008-10-31 2014-03-05 大金美国股份有限公司 发泡电线

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5350484A (en) * 1976-10-19 1978-05-08 Hitachi Cable Ltd Highly flame resistant cable

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI52156C (fi) * 1969-10-21 1977-06-10 Pirelli Taipuisalla muovilla päällystetty tulenkestävä kaapeli.
DE2114369C3 (de) * 1971-03-25 1980-05-22 Kabel- Und Metallwerke Gutehoffnungshuette Ag, 3000 Hannover Mischungen auf der Basis elektrisch isolierender Werkstoffe
US4166881A (en) * 1977-12-27 1979-09-04 Western Electric Company Top coated PVC articles

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5350484A (en) * 1976-10-19 1978-05-08 Hitachi Cable Ltd Highly flame resistant cable

Also Published As

Publication number Publication date
NO155266C (no) 1987-03-04
AU6403580A (en) 1981-05-21
JPS5684811A (en) 1981-07-10
MX152432A (es) 1985-07-15
AU541268B2 (en) 1985-01-03
CA1163688A (en) 1984-03-13
IT7927295A0 (it) 1979-11-15
ES497224A0 (es) 1981-08-01
DE3065555D1 (en) 1983-12-15
NO155266B (no) 1986-11-24
BR8007440A (pt) 1981-05-26
NZ195523A (en) 1982-12-07
EP0029234A1 (en) 1981-05-27
IT1165372B (it) 1987-04-22
ES8106629A1 (es) 1981-08-01
NO803428L (no) 1981-05-18
AR221445A1 (es) 1981-01-30
ATE5284T1 (de) 1983-11-15
JPH0230126B2 (es) 1990-07-04

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