US3272912A - Flexible tubing and the manufacture thereof - Google Patents

Flexible tubing and the manufacture thereof Download PDF

Info

Publication number
US3272912A
US3272912A US429526A US42952665A US3272912A US 3272912 A US3272912 A US 3272912A US 429526 A US429526 A US 429526A US 42952665 A US42952665 A US 42952665A US 3272912 A US3272912 A US 3272912A
Authority
US
United States
Prior art keywords
strip
jacket
folded
polyethylene
plastic
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 - Lifetime
Application number
US429526A
Other languages
English (en)
Inventor
Jachimowicz Ludwik
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.)
General Cable Corp
Original Assignee
General Cable Corp
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 General Cable Corp filed Critical General Cable Corp
Priority to US429526A priority Critical patent/US3272912A/en
Priority to ES0321799A priority patent/ES321799A1/es
Priority to SE00541/66A priority patent/SE330195B/xx
Priority to SE6713215A priority patent/SE372839B/xx
Priority to GB2469/66A priority patent/GB1139961A/en
Priority to FR47252A priority patent/FR1465904A/fr
Priority to CH124866A priority patent/CH444928A/de
Priority to DE1966G0045849 priority patent/DE1640127B2/de
Application granted granted Critical
Publication of US3272912A publication Critical patent/US3272912A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
    • H02G3/00—Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles
    • H02G3/02—Details
    • H02G3/04—Protective tubing or conduits, e.g. cable ladders or cable troughs
    • H02G3/0462—Tubings, i.e. having a closed section
    • H02G3/0481—Tubings, i.e. having a closed section with a circular cross-section
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L11/00—Hoses, i.e. flexible pipes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L11/00—Hoses, i.e. flexible pipes
    • F16L11/14—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics
    • F16L11/15—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics corrugated
    • 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
    • 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
    • H01B13/22—Sheathing; Armouring; Screening; Applying other protective layers
    • H01B13/26—Sheathing; Armouring; Screening; Applying other protective layers by winding, braiding or longitudinal lapping
    • H01B13/2613—Sheathing; Armouring; Screening; Applying other protective layers by winding, braiding or longitudinal lapping by longitudinal lapping
    • 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
    • H01B13/22—Sheathing; Armouring; Screening; Applying other protective layers
    • H01B13/26—Sheathing; Armouring; Screening; Applying other protective layers by winding, braiding or longitudinal lapping
    • H01B13/2613—Sheathing; Armouring; Screening; Applying other protective layers by winding, braiding or longitudinal lapping by longitudinal lapping
    • H01B13/262—Sheathing; Armouring; Screening; Applying other protective layers by winding, braiding or longitudinal lapping by longitudinal lapping of an outer metallic screen
    • 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
    • H01B7/20—Metal tubes, e.g. lead sheaths
    • H01B7/202—Longitudinal lapped metal tubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B9/00—Power cables
    • H01B9/02—Power cables with screens or conductive layers, e.g. for avoiding large potential gradients
    • H01B9/022—Power cables with screens or conductive layers, e.g. for avoiding large potential gradients composed of longitudinal lapped tape-conductors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
    • Y10T156/10—Methods of surface bonding and/or assembly therefor
    • Y10T156/1002—Methods of surface bonding and/or assembly therefor with permanent bending or reshaping or surface deformation of self sustaining lamina
    • Y10T156/1007—Running or continuous length work
    • Y10T156/1008—Longitudinal bending
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49117—Conductor or circuit manufacturing
    • Y10T29/49123—Co-axial cable

Definitions

  • This invention relates to sheathed electrical cables of the type in which the sheath comprises a metallic strip which is coextensive in length with the cable core and is folded about the core into the form of a tube, and in which there is an outer jacket of polyethylene extruded over the tube.
  • the longitudinal edges of the folded strip may overlap each other slightly, or they may substantially abut each other, or they may nearly abut each other with a slight gap between edges. More particularly the invention relates to such a construction in which the folded metallic strip loosely encloses the cable core, or is simply a duct or tube into which electrical wires and cables may be drawn subsequently, the folded metallic strip having insufiicient strength itself to withstand compression or collapse of the tube under the circumferential contraction during cooling of the polyethylene jacket extruded thereover in accordance with conventional practice.
  • This invention provides an article and method of production in Which circumferential contraction and/ or collapse of the tube formed by the folded strip is prevented during contraction of the extruded polyethylene jacket as it cools, even though there is no mechanical connection between the edges of the strip, and no firm support inside the tube.
  • FIGURE 1 is a diagrammatic top plan view of apparatus for making cable sheath or duct in accordance with the invention
  • FIGURE 2 is a greatly enlarged sectional view taken on the line 22 of FIGURE 1;
  • FIGURE 3 is a greatly enlarged sectional view taken on the line 3-3 of FIGURE 1;
  • FIGURE 4 is a view similar to FIGURE 3, but showing a modified form of the invention
  • FIGURE 5A is a transverse section through a cable in which the folded metallic strip loosely encloses the cable core with the strip edges overlapping, and showing the polyethylene jacket in place as the cable leaves the extruding machine, i.e., before the hot polyethylene has cooled and contracted;
  • FIGURE 5B is a view similar to FIGURE 5A showing what happens when the polyethylene jacket extruded in accordance with conventional practice cools and contracts;
  • FIGURE 6A is a view similar to FIGURE 5A, eX- cept that the folded metallic strip has fused to its outer 3 ,272,912 Patented Sept. 13, 1966 surface a thin layer of special material according to this invention;
  • FIGURE 63 is a view similar to FIGURE 6A showing what happens when the polyethylene jacket applied according to this invention cools and contracts;
  • FIGURE 7A is a view similar to FIGURE 6A, except that the longitudinal edges of the folded metallic strip are spaced slightly from each other in nearly abutting relation, instead of being overlapped;
  • FIGURE 7B is a view similar to FIGURE 7A showing What happens when the polyethylene jacket applied according to this invention cools and contracts;
  • FIGURE 8 is a diagram for illustrating the principles involved.
  • Polyethylene jacketing compound (low density) expands by volume 26% when heated from room temperature of F. to extrusion temperature of 400 F. (R. D. Biggs and R. P. Guenther, Bell Telephone Laboratories, Eleventh Annual Wire and Cable Symposium, Asbury Park, New Jersey). Volume contraction between 400 F. and 80 F., taking the hot expanded volume as a reference base, is 21%. The effects of this shrinkage must be taken into account in the manufacture of cable having a jacket of polyethylene extruded thereon.
  • the shrinkage of the extruded plastic as it cools produces only a reduction of the jacket wall thickness. Movement of the inner surface of the jacket concentrically towards the center of the cable during cooling is prevented by the firm support of the rigid lead sheath or the stalpeth steel sheath on which the jacket rests.
  • the present invention makes it possible to prevent concentric contraction of the cooling plastic jacket in types of cables having a folded strip covering in which there is no rigid member under or over the folded strip to support the jacket against such contraction.
  • Such types include the alpeth type sheath over an undersized or loose core, and empty duct or tubing,
  • the direction of shrinkage by nature three dimensional, will be restrained only in the direction of cable length. It will be free in the radial and the circumferential directions. Assuming free movement, one half of the shrinkage will occur as radial shrinkage, i.e., reduction in wall thickness, and one half will occur as circumferential shrinkage, producing a reduction in the enclosed cross sectional area. To accommodate for 21% shrinkage by volume each of these two dimensions has to shrink linearly by about 10% The radial shrinkage, i.e., shrinkage in wall thickness, is not of particular concern in this case. The circumferential shrinkage, however, is of great importance because it will produce a reduction of the diameter of the jacket. If the plastic jacket is extruded without a support of any kind it collapses, as it cools, into an irregular shape of no utility.
  • the aluminum strip In alpeth cable the aluminum strip is normally wrapped around cable core rather snugly, allowing for sliding of the strip edges by only some 30 to 50 mils. After this the free movement of the aluminum strip under the pressure of the contracting plastic jacket has been exhausted, further circumferential shrinkage of jacket builds up the pressure from the jacket against cable core. This is shown very well on the inner surface of polyethylene jackets extruded over corrugated aluminum strips. The inner surface of the plastic is pressure molded into the corrugations of the aluminum strip. This pressure comes from the cooling and shrinking outer shell of the jacket which presses the plastic against the aluminum strip, now tfirmly supported on the cable core.
  • the jacket extruded according to conventional practice continues to shrink circumferentially. As a result, the unsoldered aluminum strip collapses at the overlap. Soft jacket material flows into the collapsed region and a deformed cable or tube results with the folded aluminum strip rattling loose inside. No useful product is produced.
  • the present invention is concerned with those cases where it is desired to extrude a plastic jacket over a folded core-covering strip which is unfastened at the overlap and which encloses a soft or small core, or an empty circular cross section.
  • This invention has utility, for example, in making a sheath over und-ulated cable core, or in making tubing for the flow of gas, or in making double sheathed cable when it is required that no indentations of the corrugated metallic strip be impressed into the underlying jacket, as in Minuteman cables.
  • the metallic strip which is folded into tulbular form about the cable core is coated, at least on its outer surface, with a thin film of special polyethylene compound which is intimately fused and firmly adhered on the surface of the metallic strip.
  • This special compound described also in applicants copending application Serial No. 320,777 now Patent No. 3,233,036, comprises polyethylene containing reactive carboxyl groups which have the ability to develop very firm adhesion to the aluminum strip and also to the polyethylene jacket when it is extruded thereover.
  • Aluminum strip coated with this special compound is sometimes known as fused polyethylene aluminum strip.
  • FIGURE 1 shows a loose cable core 10 which is advanced with uniform motion in the direction indicated by the arrows 12.
  • a coated metallic strip 14 is advanced with the cable core 10 and is folded about the cable core 10 by pinch rollers 16.
  • These pinch rollers 16 are merely representative of forming apparatus for bending the strip 14 into a tubular shape'with the opposite edges 18 of the strip abutting or substantially abutting, as illustrated in FIGURE 3, or overlapping, as illustrated in FIGURE 4, along a longitudinal seam 20.
  • pinch rollers 16 are merely representative of forming apparatus for bending the strip 14 into a tubular shape'with the opposite edges 18 of the strip abutting or substantially abutting, as illustrated in FIGURE 3, or overlapping, as illustrated in FIGURE 4, along a longitudinal seam 20.
  • To simplify the illustration only one pair of pinch rollers 16 is illustrated, but it will be understood that additional forming rollers can be employed in accordance with conventional tube forming practice.
  • the coated metallic strip 14 includes a transversely corrugated aluminum strip 22.
  • the corrugations are clearly shown in FIGURE 2.
  • This inner coating is not essential to this invention, but it provides important protection for the metallic strip against corrosion.
  • the coatings 24 and 26 are applied to the metallic strip 22 before it enters the apparatus illustrated in FIGURE 1, and the laminated strip 14 may be stored on a reel (not shown) from which it is withdrawn for the forming operation illustrated in FIGURE 1.
  • the plastic coatings 24 and 26 are polyolefin plastic combined with material to produce an adhesive composition which will form a firm bond to the metallic strip 22 and to which an extruded plastic will adhere instantly upon contact.
  • the coatings 24 and 26 should be flexible protective films which have high electrical resistivity, high resistance to chemicals and moisture, and exceptionally .good adhesion to the aluminum strip 22 to withstand manufacturing processes such as the corrugating of the laminated strip 14, and to prevent delamination in corrosive atmospheres or liquids.
  • Polyethylene films generally satisfy the requirements of resistivity and resistance to chemicals and moisture. However, polyethylene does not adhere to metals with the desired bond because the polyethylene is inert and can develop only a mechanical bond based on a friction-type adhesion. Best results are obtained with a copolymer of polyethylene and acrylic groups, for example, a graft copolymer of polyethylene and a monomer with a reactive carboxyl group such as an acrylic acid or an acrylic acid ester, as described in my copending application Serial No. 320,777, now Patent No. 3,233,036, or in U.S. Patents Nos. 3,987,501 and 3,027,346.
  • the carboxyl component of the copolymer has the property of forming chemical bonds with the metals to provide the desired bonding of the film to the metal.
  • the nature of the copolymer is such that when it is applied on both sides of the aluminum strip 22 in a thickness ranging from one to three mils it will prevent direct attack on the metal surface when exposed to corrosive environments anticipated in the installation of telephone cable in varied locations. If the film coatings 24 and 26 are damaged at any point the metal may be exposed to corrosive attack at the point of damage, but the rate of degradation of the metallic strip 22 is very much slower than it would be for an uncoated metallic strip, because the corrosive action enlarging the area of the metal destroyed must proceed along the length of thestrip between the protective coatings 24 and 26 In order to so define any path of corrosion the coatings 24 and 26 must adhere to the metallic strip without delamination under the exposure to corrosive conditions and the mechanical forces of the corrosion products.
  • a strip of aluminum 8 mils thick was coated on both sides with 2 mils of the special polyethylene compound according to this invention.
  • the coated strip was corrugated transversely, the corrugation depth being 50 mils, with 9 to 10 corrugations per inch.
  • the corrugations are not essential to the present invention, but provide flexibility for the sheathed cable or duct.
  • the thickness of the metallic strip and the thickness of the strip coatings are exaggerated in FIGURES 2 through 4 and 6A through 7B, this being necessary to show the construction clearly.
  • the core with the folded tubular covering formed by the folded strip 14 passes through an extrusion jacketing station 30 wherean extruder 32 extrudes plastic 34, preferably polyethylene, by the sleeving process over the outside surface of the folded strip 14 to form a jacket 36.
  • This outer jacket 36 preferably is made of black polyethylene of the kind com monly used for the outside covering of electrical cables.
  • the outer jacket 36 is preferably of a radial thickness between 60 and 80 mils.
  • the folded strip 14 is not sticky as it enters the extruder 32, but becomes activated by the heat of the jacket when it comes into contact with the jacketing material. Once adhesion of sufficient strength is developed between the jacket 36 and the folded strip 14, the shrinkage of the jacket 36 is restricted in all directions but one, that is, in direction of the wall thickness.
  • the adhesive should be of such nature as to become stronger as it cools, because contraction forces in the jacket also increase as the jacket cools, from a few pounds per square inch when hot to about 1800 pounds per square inch when at room temperature.
  • Adhesion of the outer jacket 36 to the folded strip depends on the temperature at which the plastic 34 is extruded over the folded strip 14. It is desirable to keep the temperature of the plastic 34 within the range of 400-450" F. for high molecular weight polyethylene and for extrusion speeds of fifty feet per minute and up. This is compatible with normal manufacturing processes.
  • FIGURE 3 shows the coated metallic strip 14 formed around a loose cable core 10, and the cable core is not sufficiently large to provide any support for the folded strip 14 against circumferential contraction and collapse.
  • a supporting roll 46 can be used along the run between the forming station or pinch rollers 16 and the extrusion and jacketing station 30.
  • FIGURE 4 shows a modified construction in which the coated metallic strip 54 is formed around the cable core 10 with a lapped seam 56 instead of the butt seam of FIGURE 3. All other parts in FIGURE 4, which correspond to those in FIGURE 3, are indicated by the same reference characters, but with a prime appended.
  • FIGURES 5A and 5B illustrate what happens when a jacket of polyethylene is extruded onto the overlapping folded aluminum strip covering a loose cable core, in accordance with conventional practice.
  • FIGURES 6A and 6B show, by way of direct comparison, what happens when a jacket of polyethylene is extruded onto the overlapping folded metallic strip covering over a loose cable core, in accordance with the present invention.
  • the constructions and procedures of the tests on which these illustration-s are based were the same in both cases except that in FIGURES 5A and 5B the aluminum strip was uncoated, whereas in FIGURES 16A and 6B the aluminum strip was coated with the special adhesive polyethylene compound as described hereinabove.
  • FIGURE 5A the cable core 61 is shown loosely enclosed within the approximately cylindrical tube formed from the folded aluminum strip 62.
  • the strip edge overlapped each other, as shown.
  • the cylindrical sleeved jacket 63 of polyethylene is shown as it came hot from the extruder.
  • the polyethylene jacket 63 cooled it contracted circumferentially, causing the overlapping edges of the aluminum strip to slide, one with respect to the other, thus reducing the cross sectional area enclosed by the folded strip and distorting the original substantially cylindrical shape.
  • the outermost edge of the strip gouged into the polyethylene jacket and made it thinner directly over the strip edge than elsewhere around the periphery. This result is shown in FIGURE 5B.
  • FIGURE 6A the cable core 61 is shown loosely enclosed within the approximately cylindrical tube formed by the folded aluminum strip 62', the strip edges overlapping each other as shown.
  • FIGURE 7A shows the construction with the polyethylene jacket in cylindrical form, still hot, as sleeved onto the folded strip 62" of aluminum having on its outer surface a coating of the special adhesive compound, in accordance with this invention.
  • Instant adherence of the hot jacket 63" to the folded strip 62" prevented movement of the jacket relative to the surface of the strip.
  • the material of the jacket 63 cooled it was restricted to contraction in a radial direction except only for a very narrow circumferential area over the gap between the edges of the folded strip. The contraction resulted in a thinning of the jacket 63" except at the slight gap between the edges of the folded strip, where the compound did enter slightly and bulge down into the gap, as shown in FIGURE 7B.
  • the inner surface of the jacket In order to prevent circumferential shrinkage of the thermoplastic jacket as it coo-ls the inner surface of the jacket must retain a constant circumferential length in spite of the shrinkage of the mass of the overlying jacketing material.
  • conventional alpeth cable there is no adhesion of the polyethylene jacket to the aluminum and the cooling of the extruded jacket causes the aluminum tube to col-lapse partially until it is supported by the cable core.
  • the polyethylene jacket adheres firmly to the special adhesive polyethylene coating on the metallic strip at the time of extrusion and there is no collapsing of the metallic tube.
  • FIG. 8 For stresses in a compressed aluminum column the following formula is given in the handbook, Aluminum Structural 7 Design, by Reynolds Metal Company, Louisville 1, Kentucky, 1951:
  • the strip will collapse and the jacket will shrink circumferentially.
  • the actual mechanics of preventing circumferential shrinkage of the jacket is more complex.
  • the force S is small, because the jacket is in a molten state. So is the bond between the jacket and the molten coating of the strip at points A and B.
  • the copolymer coating of the strip which, being also polyethylene, cools and acquires strength in the same temperature bracket as the jacketing material.
  • the bonding to the metal increases, and with it the ability to convey the forces to the metal.
  • stresses in the jacket are conveyed to the aluminum strip which supports them without collapsing or wrinkling.
  • a cable according to claim 1 in which there is a thin layer of plastic highly adhesive to metal firmly bonded to the outside surface of the metallic strip and in which the relatively thicker overlying plastic jacket is bonded to the thin layer of adhesive plastic.
  • a cable according to claim 2 characterized by the thin layer of adhesive plastic on the metallic strip being a copolymer of ethylene and a monomer containing reactive carboxyl group.
  • a flexible duct comprising a metal strip of indefinite length folded into tubular form with the strip edges free for relative movement, a thin layer of a highly adhesive plastic firmly bonded to the outer surface of the strip, and a relatively thicker jacket of plastic having a high coeflicient'of expansion enclosing and firmly bonded to the thin layer of adhesive plastic so as to prevent relative movement between the outer plastic jacket and the folded strip and between the strip edges.
  • the flexible duct described in claim 4 characterized by the strip being corrugated with transversely extending corrugations throughout the full width of the strip.
  • the flexible duct described in claim 4 characterized by the layer of adhesive plastic on the strip being a graft copolymer of polyethylene and a monomer with a reactive carboxyl group.
  • the flexible duct described in claim 6 characterized by the coating on the strip being a graft copolymer of polyethylene and a monomer with a reactive carboxyl group including an acrylic acid ester, the aluminum strip being between five to ten mils thick and the coating on the aluminum strip being from one to three mils thick.
  • the flexible duct described in claim 4 characterized by the strip being aluminum approximately eight mils in thickness and coated with adhesive plastic to a thickness of approximately two mils, and the strip being corrugated transversely with corrugations having a depth of approximately fifty mils and about five to ten corrugations per inch of length of the sheet.
  • the flexible duct described in claim 4 characterized by the cross section of the tube' being substantially circular and the longitudinal edge portions of the tube overlapping one another.
  • the method of making a plastic jacketed metallic duct of preselected tubular cross section and size and in which the plastic jacketing material, having a high coeflicient of expansion, is extruded hot onto the preformed metallic duct comprises moving a metallic strip in the direction of its longitudinal axis, continuously folding the strip into the preselected tubular cross section and size'while leaving the adjacent longitudinal edges of the folded strip free to move relative to each other, extruding the jacketing material hot onto the tubular form, and preventing circumferential contraction of the tubular form as the jacketing material cools by causing the hot jacketing material to adhere firmly to the tubular form around its periphery at the instant of contact and by such adherence to reinforce the tubular form against collapse.
  • the method of making a plastic jacketed duct which comprises bonding to one surface of a strip of indefinite length a thin coating of a firmly adhering plastic material, moving the strip longitudinally and continuously folding the strip into tubular form with the plastic coating on the outside of the tubular form and with the edges of the strip free to move relative to each other, and sleeving a tube of plastic jacketing compound having a high coefiicient of expansion onto the tubular form at a temperature which will activate the coating on the folded strip to produce instant bonding between the said coating and the jacketing materialat the interface to reinforce the folded strip against collapse and prevent circumferential contraction of the jacket and relative movement between the strip edges.
  • the method of making a plastic jacketed electrical cable which comprises bonding to one surface of a metallic strip a thin coating of a firmly adhering plastic material, drawing the strip along a moving conductor core, continuously folding the strip into tubular form about the moving core with the plastic coating on the outside of the tubular form while leaving the longitudinal edges of the strip free to move relative to each other, and sleeving a tube of plastic jacketing compound having a high coefiicient of expansion onto the tubular form at a temperature which will activate the coating on the folded strip to produce instant bonding between the said coating and the jacketing material at the interface to reinforce the folded strip against collapse and prevent circumferential contraction of the jacket and relative movement between the strip edges.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Structural Engineering (AREA)
  • Civil Engineering (AREA)
  • Architecture (AREA)
  • Insulated Conductors (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Laminated Bodies (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Protection Of Pipes Against Damage, Friction, And Corrosion (AREA)
  • Manufacturing Of Electric Cables (AREA)
US429526A 1965-02-01 1965-02-01 Flexible tubing and the manufacture thereof Expired - Lifetime US3272912A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US429526A US3272912A (en) 1965-02-01 1965-02-01 Flexible tubing and the manufacture thereof
SE00541/66A SE330195B (de) 1965-02-01 1966-01-14
SE6713215A SE372839B (de) 1965-02-01 1966-01-14
ES0321799A ES321799A1 (es) 1965-02-01 1966-01-14 Perfeccionamientos en la construccion de tubos o conductos flexibles.
GB2469/66A GB1139961A (en) 1965-02-01 1966-01-19 Flexible tubing and the manufacture thereof
FR47252A FR1465904A (fr) 1965-02-01 1966-01-26 Câble électrique blindé
CH124866A CH444928A (de) 1965-02-01 1966-01-27 Ummanteltes elektrisches Kabel und Verfahren zu seiner Herstellung
DE1966G0045849 DE1640127B2 (de) 1965-02-01 1966-01-28 Biegsames rohr mit einem rohrfoermigen bandkoerper und thermoplastischer kunststoffummantelung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US429526A US3272912A (en) 1965-02-01 1965-02-01 Flexible tubing and the manufacture thereof

Publications (1)

Publication Number Publication Date
US3272912A true US3272912A (en) 1966-09-13

Family

ID=23703631

Family Applications (1)

Application Number Title Priority Date Filing Date
US429526A Expired - Lifetime US3272912A (en) 1965-02-01 1965-02-01 Flexible tubing and the manufacture thereof

Country Status (7)

Country Link
US (1) US3272912A (de)
CH (1) CH444928A (de)
DE (1) DE1640127B2 (de)
ES (1) ES321799A1 (de)
FR (1) FR1465904A (de)
GB (1) GB1139961A (de)
SE (2) SE330195B (de)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3964945A (en) * 1972-04-07 1976-06-22 E. I. Du Pont De Nemours And Company Method of making an electrical cable
US4071388A (en) * 1973-11-26 1978-01-31 Sumitomo Electric Industries, Ltd. Impulse heat joining of wrapping tapes for wire cables
US4079190A (en) * 1977-02-03 1978-03-14 International Standard Electric Corporation Submarine coaxial cable
US4151365A (en) * 1977-08-22 1979-04-24 Western Electric Company, Inc. Filled service cable having corrugated shield and methods of making
US4327248A (en) * 1980-10-06 1982-04-27 Eaton Corporation Shielded electrical cable
US4454379A (en) * 1982-05-21 1984-06-12 General Electric Company Semi-conductive, moisture barrier shielding tape and cable
US4515992A (en) * 1983-05-10 1985-05-07 Commscope Company Cable with corrosion inhibiting adhesive
US4563540A (en) * 1984-06-29 1986-01-07 At&T Technologies, Inc. Bonded sheath cable
US4569704A (en) * 1984-06-29 1986-02-11 At&T Technologies, Inc. Methods of making a bonded sheath cable
US4622092A (en) * 1984-06-29 1986-11-11 At&T Technologies Apparatus for making a bonded sheath cable
US4758455A (en) * 1985-07-10 1988-07-19 Handy & Harman Automotive Group Inc. Composite fuel and vapor tube having increased heat resistance
US5528824A (en) * 1993-05-18 1996-06-25 Baker Hughes Incorporated Method of forming a double armor cable with auxiliary line for an electrical submersible pump
US5626167A (en) * 1992-02-12 1997-05-06 Sofanou S.A. Tubular sheath sound insulation for electric cables and a process for its production
US20090314517A1 (en) * 2008-06-23 2009-12-24 Allen Jerry L Communications cable with fabric sleeve
US20110067920A1 (en) * 2009-09-24 2011-03-24 Yazaki Corporation Wiring harness having protection member
US10234649B2 (en) * 2017-07-03 2019-03-19 Wesco Distribution, Inc. Fabric encased micro tubes for air blown fibers
CN111768934A (zh) * 2020-06-02 2020-10-13 无锡恒泰电缆机械制造有限公司 一种钢带铠装用同心式放带机
EP4184050A1 (de) * 2021-11-23 2023-05-24 Johns Manville Aussenverkleidung für dämmsysteme

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2540273C2 (de) * 1975-09-10 1983-11-24 Witzenmann GmbH, Metallschlauch-Fabrik Pforzheim, 7530 Pforzheim Mehrlagiger Wellschlauch und Vorrichtung zu seiner Herstellung
FR2486721A1 (fr) * 1980-07-09 1982-01-15 Cables De Lyon Geoffroy Delore Procede de fabrication de guides d'ondes et guides d'ondes obtenus
US4497537A (en) * 1983-06-09 1985-02-05 Bicc Public Limited Company Electric and/or optical cable
DE69103264T2 (de) * 1990-03-15 1994-11-24 Gore & Ass Katheterbekleidung und verfahren zu ihrer herstellung.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1702332A (en) * 1925-01-27 1929-02-19 Apt Richard Electric cable and method of manufacturing same
US2987501A (en) * 1958-11-05 1961-06-06 Dow Chemical Co Process for making graft copolymers of polyethylene and polypropylene
US3027346A (en) * 1956-11-15 1962-03-27 Union Carbide Corp Process for preparing composition containing graft copolymer of polyethylene and an acrylate monomer
US3130256A (en) * 1960-07-04 1964-04-21 Mildner Raymond Charles Cables for transmitting high-frequency currents

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1702332A (en) * 1925-01-27 1929-02-19 Apt Richard Electric cable and method of manufacturing same
US3027346A (en) * 1956-11-15 1962-03-27 Union Carbide Corp Process for preparing composition containing graft copolymer of polyethylene and an acrylate monomer
US2987501A (en) * 1958-11-05 1961-06-06 Dow Chemical Co Process for making graft copolymers of polyethylene and polypropylene
US3130256A (en) * 1960-07-04 1964-04-21 Mildner Raymond Charles Cables for transmitting high-frequency currents

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3964945A (en) * 1972-04-07 1976-06-22 E. I. Du Pont De Nemours And Company Method of making an electrical cable
US4071388A (en) * 1973-11-26 1978-01-31 Sumitomo Electric Industries, Ltd. Impulse heat joining of wrapping tapes for wire cables
US4079190A (en) * 1977-02-03 1978-03-14 International Standard Electric Corporation Submarine coaxial cable
US4151365A (en) * 1977-08-22 1979-04-24 Western Electric Company, Inc. Filled service cable having corrugated shield and methods of making
US4327248A (en) * 1980-10-06 1982-04-27 Eaton Corporation Shielded electrical cable
US4454379A (en) * 1982-05-21 1984-06-12 General Electric Company Semi-conductive, moisture barrier shielding tape and cable
US4515992A (en) * 1983-05-10 1985-05-07 Commscope Company Cable with corrosion inhibiting adhesive
US4563540A (en) * 1984-06-29 1986-01-07 At&T Technologies, Inc. Bonded sheath cable
US4569704A (en) * 1984-06-29 1986-02-11 At&T Technologies, Inc. Methods of making a bonded sheath cable
US4622092A (en) * 1984-06-29 1986-11-11 At&T Technologies Apparatus for making a bonded sheath cable
US4758455A (en) * 1985-07-10 1988-07-19 Handy & Harman Automotive Group Inc. Composite fuel and vapor tube having increased heat resistance
US5626167A (en) * 1992-02-12 1997-05-06 Sofanou S.A. Tubular sheath sound insulation for electric cables and a process for its production
US5528824A (en) * 1993-05-18 1996-06-25 Baker Hughes Incorporated Method of forming a double armor cable with auxiliary line for an electrical submersible pump
US20090314517A1 (en) * 2008-06-23 2009-12-24 Allen Jerry L Communications cable with fabric sleeve
US9054507B2 (en) * 2008-06-23 2015-06-09 Wesco Distribution, Inc. Communications cable with fabric sleeve
US10862280B2 (en) 2008-06-23 2020-12-08 Wesco Distribution, Inc. Communications cable with fabric sleeve
US20110067920A1 (en) * 2009-09-24 2011-03-24 Yazaki Corporation Wiring harness having protection member
US10234649B2 (en) * 2017-07-03 2019-03-19 Wesco Distribution, Inc. Fabric encased micro tubes for air blown fibers
CN111768934A (zh) * 2020-06-02 2020-10-13 无锡恒泰电缆机械制造有限公司 一种钢带铠装用同心式放带机
EP4184050A1 (de) * 2021-11-23 2023-05-24 Johns Manville Aussenverkleidung für dämmsysteme
US11835169B2 (en) 2021-11-23 2023-12-05 Johns Manville Exterior cladding for insulation systems

Also Published As

Publication number Publication date
SE330195B (de) 1970-11-09
CH444928A (de) 1967-10-15
ES321799A1 (es) 1967-01-16
SE372839B (de) 1975-01-13
GB1139961A (en) 1969-01-15
DE1640127A1 (de) 1970-12-10
DE1640127B2 (de) 1977-05-18
FR1465904A (fr) 1967-01-13

Similar Documents

Publication Publication Date Title
US3272912A (en) Flexible tubing and the manufacture thereof
US4791966A (en) Wrapped, elongated stock
JP4023771B2 (ja) 同軸ケーブルおよびその製造法
US3037529A (en) Laminated tube structure and method
US3379821A (en) Shielded electrical cable
AU724140B2 (en) Coaxial cable
US4016356A (en) Heat recoverable article
US3321572A (en) Dual laminated telephone cable sheath
US3576939A (en) Electrical cables and method of making same
US3829340A (en) Methods of making a tubular member having a sealed longitudinal seam
US3634606A (en) Outer conductor for coaxial cable
US3575748A (en) Method of making electrical cable
US3813272A (en) Method and apparatus for simultaneously applying to an extended cylinmethod and apparatus for simultaneously applying to an extended cylindrical object a coating and a plastic film wrapping to retain the coating
US4225749A (en) Sealed power cable
US3823747A (en) Tubular member having a sealed longitudinal seam
US4134782A (en) Method for simultaneously applying to an extended cylindrical object a coating and a plastic film wrapping to retain the coating
US3660589A (en) Watertight disc coaxial cable
US3504102A (en) Laminated cable jacket with sealed and reinforced seam
KR860006662A (ko) 열절연 콘디트 튜브의 제조방법
US3766645A (en) Method of making electrical cables
US3819434A (en) Methods of making communications cables with sealed metallic moisture barriers
US9691524B2 (en) Systems and methods for applying metallic laminates to cables
US3325321A (en) Method of making coaxial electric cables
US3761332A (en) Watertight disc coaxial cable
US3530019A (en) Apparatus and method for making laminated cable sheath