CA2429985C - Process for the production of a multipolar cable, and multipolar cable produced therefrom - Google Patents

Process for the production of a multipolar cable, and multipolar cable produced therefrom Download PDF

Info

Publication number: CA2429985C
Authority: CA; Canada
Prior art keywords: layer; polymeric material; cores; multipolar cable; cable
Prior art date: 2000-11-30
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 - Lifetime

Application number

CA2429985A

Other languages

English (en)

French (fr)

Other versions

CA2429985A1 (en

Inventor

Sergio Belli

Alberto Bareggi

Paolo Veggetti

Luca Balconi

Paolo Bossi

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.)

Prysmian Cavi e Sistemi Energia SRL

Original Assignee

Prysmian Cavi e Sistemi Energia SRL

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.)

2000-11-30

Filing date

2001-11-22

Publication date

2012-02-21

2001-11-22 Application filed by Prysmian Cavi e Sistemi Energia SRL filed Critical Prysmian Cavi e Sistemi Energia SRL

2002-06-06 Publication of CA2429985A1 publication Critical patent/CA2429985A1/en

2012-02-21 Application granted granted Critical

2012-02-21 Publication of CA2429985C publication Critical patent/CA2429985C/en

2021-11-22 Anticipated expiration legal-status Critical

Status Expired - Lifetime legal-status Critical Current

Links

238000000034 method Methods 0.000 title claims abstract description 25
238000004519 manufacturing process Methods 0.000 title claims abstract description 21
239000000463 material Substances 0.000 claims abstract description 95
238000011049 filling Methods 0.000 claims abstract description 63
238000001125 extrusion Methods 0.000 claims abstract description 49
238000010292 electrical insulation Methods 0.000 claims abstract description 11
238000000151 deposition Methods 0.000 claims abstract description 7
239000005977 Ethylene Substances 0.000 claims description 31
VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 30
-1 polypropylene Polymers 0.000 claims description 26
229920001577 copolymer Polymers 0.000 claims description 22
229920001155 polypropylene Polymers 0.000 claims description 20
239000004743 Polypropylene Substances 0.000 claims description 19
239000000203 mixture Substances 0.000 claims description 18
229920000642 polymer Polymers 0.000 claims description 16
238000004804 winding Methods 0.000 claims description 9
229920000089 Cyclic olefin copolymer Polymers 0.000 claims description 8
229920000098 polyolefin Polymers 0.000 claims description 8
229920001038 ethylene copolymer Polymers 0.000 claims description 5
150000002148 esters Chemical class 0.000 claims description 4
QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 4
125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 4
230000008021 deposition Effects 0.000 claims description 2
150000001993 dienes Chemical class 0.000 claims 3
229920001198 elastomeric copolymer Polymers 0.000 claims 1
239000004698 Polyethylene Substances 0.000 description 16
229920000573 polyethylene Polymers 0.000 description 16
238000001816 cooling Methods 0.000 description 12
229910052751 metal Inorganic materials 0.000 description 11
239000002184 metal Substances 0.000 description 11
239000000945 filler Substances 0.000 description 9
229920000181 Ethylene propylene rubber Polymers 0.000 description 8
238000009826 distribution Methods 0.000 description 8
229920001169 thermoplastic Polymers 0.000 description 8
238000009434 installation Methods 0.000 description 7
239000004416 thermosoftening plastic Substances 0.000 description 7
150000001336 alkenes Chemical class 0.000 description 6
230000015572 biosynthetic process Effects 0.000 description 6
229920000728 polyester Polymers 0.000 description 6
RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 5
208000027418 Wounds and injury Diseases 0.000 description 5
229910052802 copper Inorganic materials 0.000 description 5
239000010949 copper Substances 0.000 description 5
CGPRUXZTHGTMKW-UHFFFAOYSA-N ethene;ethyl prop-2-enoate Chemical compound C=C.CCOC(=O)C=C CGPRUXZTHGTMKW-UHFFFAOYSA-N 0.000 description 5
230000001788 irregular Effects 0.000 description 5
244000043261 Hevea brasiliensis Species 0.000 description 4
UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 4
XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 description 4
229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 4
239000004676 acrylonitrile butadiene styrene Substances 0.000 description 4
229920005549 butyl rubber Polymers 0.000 description 4
239000007789 gas Substances 0.000 description 4
239000011159 matrix material Substances 0.000 description 4
229920003052 natural elastomer Polymers 0.000 description 4
229920001194 natural rubber Polymers 0.000 description 4
229920001707 polybutylene terephthalate Polymers 0.000 description 4
229920000139 polyethylene terephthalate Polymers 0.000 description 4
239000005020 polyethylene terephthalate Substances 0.000 description 4
229920002635 polyurethane Polymers 0.000 description 4
239000004814 polyurethane Substances 0.000 description 4
239000011347 resin Substances 0.000 description 4
229920005989 resin Polymers 0.000 description 4
YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 3
239000003570 air Substances 0.000 description 3
239000003795 chemical substances by application Substances 0.000 description 3
KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
238000010276 construction Methods 0.000 description 3
229920001971 elastomer Polymers 0.000 description 3
JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 3
230000003287 optical effect Effects 0.000 description 3
230000002787 reinforcement Effects 0.000 description 3
150000004756 silanes Chemical class 0.000 description 3
238000003860 storage Methods 0.000 description 3
229920002725 thermoplastic elastomer Polymers 0.000 description 3
LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 2
KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 description 2
IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
239000004952 Polyamide Substances 0.000 description 2
239000004793 Polystyrene Substances 0.000 description 2
ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
125000003118 aryl group Chemical group 0.000 description 2
CQEYYJKEWSMYFG-UHFFFAOYSA-N butyl acrylate Chemical compound CCCCOC(=O)C=C CQEYYJKEWSMYFG-UHFFFAOYSA-N 0.000 description 2
239000002131 composite material Substances 0.000 description 2
230000000694 effects Effects 0.000 description 2
HQQADJVZYDDRJT-UHFFFAOYSA-N ethene;prop-1-ene Chemical group C=C.CC=C HQQADJVZYDDRJT-UHFFFAOYSA-N 0.000 description 2
229920001684 low density polyethylene Polymers 0.000 description 2
239000004702 low-density polyethylene Substances 0.000 description 2
239000000320 mechanical mixture Substances 0.000 description 2
238000002156 mixing Methods 0.000 description 2
239000002245 particle Substances 0.000 description 2
150000002978 peroxides Chemical class 0.000 description 2
229920001568 phenolic resin Polymers 0.000 description 2
239000005011 phenolic resin Substances 0.000 description 2
229920002492 poly(sulfone) Polymers 0.000 description 2
229920002647 polyamide Polymers 0.000 description 2
239000004417 polycarbonate Substances 0.000 description 2
229920000515 polycarbonate Polymers 0.000 description 2
229920000570 polyether Polymers 0.000 description 2
229920002223 polystyrene Polymers 0.000 description 2
239000004800 polyvinyl chloride Substances 0.000 description 2
239000005060 rubber Substances 0.000 description 2
229910000030 sodium bicarbonate Inorganic materials 0.000 description 2
235000017557 sodium bicarbonate Nutrition 0.000 description 2
239000000126 substance Substances 0.000 description 2
229920001897 terpolymer Polymers 0.000 description 2
PRBHEGAFLDMLAL-GQCTYLIASA-N (4e)-hexa-1,4-diene Chemical compound C\C=C\CC=C PRBHEGAFLDMLAL-GQCTYLIASA-N 0.000 description 1
BHNZEZWIUMJCGF-UHFFFAOYSA-N 1-chloro-1,1-difluoroethane Chemical compound CC(F)(F)Cl BHNZEZWIUMJCGF-UHFFFAOYSA-N 0.000 description 1
BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical class OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 1
241000272470 Circus Species 0.000 description 1
241000518994 Conta Species 0.000 description 1
229920002943 EPDM rubber Polymers 0.000 description 1
229920003345 Elvax® Polymers 0.000 description 1
208000034693 Laceration Diseases 0.000 description 1
229920003346 Levapren® Polymers 0.000 description 1
239000004721 Polyphenylene oxide Substances 0.000 description 1
229910000831 Steel Inorganic materials 0.000 description 1
YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 1
239000000654 additive Substances 0.000 description 1
239000004411 aluminium Substances 0.000 description 1
229910052782 aluminium Inorganic materials 0.000 description 1
XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
XOZUGNYVDXMRKW-AATRIKPKSA-N azodicarbonamide Chemical compound NC(=O)\N=N\C(N)=O XOZUGNYVDXMRKW-AATRIKPKSA-N 0.000 description 1
238000009835 boiling Methods 0.000 description 1
239000001273 butane Substances 0.000 description 1
229910052799 carbon Inorganic materials 0.000 description 1
239000001569 carbon dioxide Substances 0.000 description 1
229910002092 carbon dioxide Inorganic materials 0.000 description 1
150000004649 carbonic acid derivatives Chemical class 0.000 description 1
150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
239000011248 coating agent Substances 0.000 description 1
238000000576 coating method Methods 0.000 description 1
239000004020 conductor Substances 0.000 description 1
239000000110 cooling liquid Substances 0.000 description 1
239000003431 cross linking reagent Substances 0.000 description 1
230000003247 decreasing effect Effects 0.000 description 1
230000003111 delayed effect Effects 0.000 description 1
229920003244 diene elastomer Polymers 0.000 description 1
238000001035 drying Methods 0.000 description 1
239000000806 elastomer Substances 0.000 description 1
230000007613 environmental effect Effects 0.000 description 1
239000012530 fluid Substances 0.000 description 1
239000008187 granular material Substances 0.000 description 1
150000008282 halocarbons Chemical class 0.000 description 1
FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 1
229920001519 homopolymer Polymers 0.000 description 1
229930195733 hydrocarbon Natural products 0.000 description 1
150000002430 hydrocarbons Chemical class 0.000 description 1
238000009413 insulation Methods 0.000 description 1
230000001678 irradiating effect Effects 0.000 description 1
238000011068 loading method Methods 0.000 description 1
TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
229910052757 nitrogen Inorganic materials 0.000 description 1
239000000615 nonconductor Substances 0.000 description 1
239000013307 optical fiber Substances 0.000 description 1
150000007524 organic acids Chemical class 0.000 description 1
235000005985 organic acids Nutrition 0.000 description 1
239000001294 propane Substances 0.000 description 1
230000001681 protective effect Effects 0.000 description 1
230000005855 radiation Effects 0.000 description 1
150000003254 radicals Chemical class 0.000 description 1
238000012216 screening Methods 0.000 description 1
238000007789 sealing Methods 0.000 description 1
239000010959 steel Substances 0.000 description 1
CYRMSUTZVYGINF-UHFFFAOYSA-N trichlorofluoromethane Chemical compound FC(Cl)(Cl)Cl CYRMSUTZVYGINF-UHFFFAOYSA-N 0.000 description 1
229940029284 trichlorofluoromethane Drugs 0.000 description 1
238000009827 uniform distribution Methods 0.000 description 1
238000011144 upstream manufacturing Methods 0.000 description 1
229920001567 vinyl ester resin Polymers 0.000 description 1
125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
229920002554 vinyl polymer Polymers 0.000 description 1
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
235000020681 well water Nutrition 0.000 description 1
239000002349 well water Substances 0.000 description 1

Classifications

- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
- H01B13/06—Insulating conductors or cables
- H01B13/14—Insulating conductors or cables by extrusion
- H01B13/141—Insulating conductors or cables by extrusion of two or more insulating layers
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B9/00—Power cables
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
- H01B13/06—Insulating conductors or cables
- H01B13/14—Insulating conductors or cables by extrusion
- H01B13/142—Insulating conductors or cables by extrusion of cellular material
- 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
- H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
- H01B7/18—Protection against damage caused by wear, mechanical force or pressure; Sheaths; Armouring
- H01B7/1895—Internal space filling-up means

Landscapes

Engineering & Computer Science (AREA)
Manufacturing & Machinery (AREA)
Extrusion Moulding Of Plastics Or The Like (AREA)
Insulated Conductors (AREA)
Communication Cables (AREA)
Coupling Device And Connection With Printed Circuit (AREA)

CA2429985A 2000-11-30 2001-11-22 Process for the production of a multipolar cable, and multipolar cable produced therefrom Expired - Lifetime CA2429985C (en)

Applications Claiming Priority (4)

Application Number	Priority Date	Filing Date	Title
EP00126132		2000-11-30
EP00126132.0		2000-11-30
US25187000P	2000-12-08	2000-12-08
PCT/EP2001/013579 WO2002045100A1 (en)	2000-11-30	2001-11-22	Process for the production of a multipolar cable, and multipolar cable produced therefrom

Publications (2)

Publication Number	Publication Date
CA2429985A1 CA2429985A1 (en)	2002-06-06
CA2429985C true CA2429985C (en)	2012-02-21

Family

ID=27798770

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
CA2429985A Expired - Lifetime CA2429985C (en)	2000-11-30	2001-11-22	Process for the production of a multipolar cable, and multipolar cable produced therefrom

Country Status (9)

Country	Link
EP (1)	EP1346376B1 (de)
AT (1)	ATE362637T1 (de)
AU (2)	AU2002227940B2 (de)
BR (1)	BR0115739B1 (de)
CA (1)	CA2429985C (de)
DE (1)	DE60128485T2 (de)
ES (1)	ES2287177T3 (de)
PT (1)	PT1346376E (de)
WO (1)	WO2002045100A1 (de)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US7166802B2 (en)	2004-12-27	2007-01-23	Prysmian Cavi E Sistemi Energia S.R.L.	Electrical power cable having expanded polymeric layers
EP1905045B1 (de)	2005-07-15	2016-05-04	Prysmian S.p.A.	Kabel mit erweitertem, abmantelbarem mantel
CN100546797C (zh) *	2006-09-06	2009-10-07	中国科学技术大学	紫外光交联聚烯烃绝缘电线电缆的生产方法及其紫外光辐照交联设备
US8886334B2 (en)	2008-10-07	2014-11-11	Mc10, Inc.	Systems, methods, and devices using stretchable or flexible electronics for medical applications
CN113077930A (zh) *	2021-04-13	2021-07-06	宁波容合电线有限公司	一种热膨胀纱线填充线缆及其加工工艺

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
DE1515709A1 (de) *	1962-10-19	1969-06-12	Felten & Guilleaume Carlswerk	Kaeltefestes elektrisches Kabel
DE8103947U1 (de) *	1981-02-13	1989-11-16	U. I. Lapp KG, 7000 Stuttgart	Elektrische Geräte- und Maschinenanschlußleitung mit besonderer mechanischer Beständigkeit und Flexibilität
DE9216118U1 (de) *	1992-04-28	1993-02-25	Dätwyler AG Kabel und Systeme, Altdorf	Kabel
DK0981821T3 (da) *	1997-05-15	2002-10-21	Pirelli Cavi E Sistemi Spa	Kabel med stødresistent coating
PT1042763E (pt) *	1997-12-22	2003-09-30	Pirelli	Cabo electrico tendo uma camada expandida semicondutora bloqueante a agua

2001
- 2001-11-22 AT AT01989502T patent/ATE362637T1/de not_active IP Right Cessation
- 2001-11-22 AU AU2002227940A patent/AU2002227940B2/en not_active Expired
- 2001-11-22 EP EP01989502A patent/EP1346376B1/de not_active Expired - Lifetime
- 2001-11-22 PT PT01989502T patent/PT1346376E/pt unknown
- 2001-11-22 DE DE60128485T patent/DE60128485T2/de not_active Expired - Lifetime
- 2001-11-22 ES ES01989502T patent/ES2287177T3/es not_active Expired - Lifetime
- 2001-11-22 AU AU2794002A patent/AU2794002A/xx active Pending
- 2001-11-22 WO PCT/EP2001/013579 patent/WO2002045100A1/en not_active Ceased
- 2001-11-22 BR BRPI0115739-6A patent/BR0115739B1/pt not_active IP Right Cessation
- 2001-11-22 CA CA2429985A patent/CA2429985C/en not_active Expired - Lifetime

Also Published As

Publication number	Publication date
EP1346376A1 (de)	2003-09-24
CA2429985A1 (en)	2002-06-06
EP1346376B1 (de)	2007-05-16
BR0115739A (pt)	2003-09-16
PT1346376E (pt)	2007-08-27
ATE362637T1 (de)	2007-06-15
AU2002227940B2 (en)	2005-09-29
AU2794002A (en)	2002-06-11
DE60128485D1 (de)	2007-06-28
DE60128485T2 (de)	2008-01-10
WO2002045100A1 (en)	2002-06-06
ES2287177T3 (es)	2007-12-16
BR0115739B1 (pt)	2011-06-14

Legal Events

Date	Code	Title	Description
2006-09-11	EEER	Examination request
2022-01-24	MKEX	Expiry	Effective date: 20211122

Publication	Publication Date	Title
CA2589166C (en)	2013-07-02	Electrical power cable having expanded polymeric layers
CN100511494C (zh)	2009-07-08	制造电缆的连续方法
AU768890B2 (en)	2004-01-08	Electric cable resistant to water penetration
US6455769B1 (en)	2002-09-24	Electrical cable having a semiconductive water-blocking expanded layer
CA2614027C (en)	2013-09-24	Cable having expanded, strippable jacket
US7816607B2 (en)	2010-10-19	Process for the production of a multipolar cable, and multipolar cable produced therefrom
JP4700061B2 (ja)	2011-06-15	ケーブルの製造方法
CA2429985C (en)	2012-02-21	Process for the production of a multipolar cable, and multipolar cable produced therefrom
AU2002227940A1 (en)	2002-08-15	Process for the production of a multipolar cable, and multipolar cable produced therefrom
KR20060115989A (ko)	2006-11-13	전기 케이블의 연속적인 제조 방법
AU743935B2 (en)	2002-02-07	Electrical cable having a semiconductive water-blocking expanded layer
PL205143B1 (pl)	2010-03-31	Ciągły proces wytwarzania kabli elektrycznych
HK1101521B (en)	2010-04-09	Continuous process for manufacturing electrical cables