GB2052360A - Improvements in or relating to manufacture of reinforced hose - Google Patents

Improvements in or relating to manufacture of reinforced hose Download PDF

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Publication number
GB2052360A
GB2052360A GB8018094A GB8018094A GB2052360A GB 2052360 A GB2052360 A GB 2052360A GB 8018094 A GB8018094 A GB 8018094A GB 8018094 A GB8018094 A GB 8018094A GB 2052360 A GB2052360 A GB 2052360A
Authority
GB
United Kingdom
Prior art keywords
hose
liner
adhesive
reinforcement structure
assembly
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.)
Granted
Application number
GB8018094A
Other versions
GB2052360B (en
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.)
Dunlop Ltd
Original Assignee
Dunlop Ltd
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 Dunlop Ltd filed Critical Dunlop Ltd
Priority to GB8018094A priority Critical patent/GB2052360B/en
Publication of GB2052360A publication Critical patent/GB2052360A/en
Application granted granted Critical
Publication of GB2052360B publication Critical patent/GB2052360B/en
Expired legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29DPRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D23/00Producing tubular articles
    • B29D23/001Pipes; Pipe joints
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/15Extrusion 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
    • B29C48/151Coating hollow articles
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16LPIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L11/00Hoses, i.e. flexible pipes
    • F16L11/04Hoses, i.e. flexible pipes made of rubber or flexible plastics
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03Extrusion 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
    • B29C48/09Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2021/00Use of unspecified rubbers as moulding material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2027/00Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/06PVC, i.e. polyvinylchloride
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)

Abstract

The hose comprises an inner liner 11 of elastomeric material, a reinforcement structure 13 and an outer cover 15 of elastomer. The outer cover 15 is formed by extrusion and the heat imparted to the assembly of liner 11 and reinforcement structure 13 during said extrusion is utilised to effect simultaneously bonding of the liner 11 to the reinforcement structure 13, either by activating an adhesive on the liner and/or the reinforcement, or by softening of the liner. <IMAGE>

Description

SPECIFICATION Improvements in or relating to hose This invention concerns improvements in or relating to hose and in particular to hose of the type comprising an inner liner of fluid impermeable elastomeric material, a tubular reinforcement structure and an outer cover of elastomeric material.
Up to now a conventional method of manufactur; ing hose of the above-described type. has involved forming an assembly of the reinforcement structure and outer cover, pulling an inner liner through the assembly and subsequently inflating the liner with steam under pressure to effect bonding of the liner to the reinforcement structure.
A disadvantage of this method is that the steps of applying the outer cover and bonding the inner liner to the reinforcement structure are separate and it is necessary to lay out the hose assembly for inflation.
As a result a large floor area is required to carry out the process especially where long lengths of hose are to be made.
According to one aspect of the present invention we provide a method of hose manufacture comprising providing an assembly of a tubular reinforcement structure and an inner liner of elastomeric material with an-extruded outer cover of elastomeric material, the heat imparted to the hose assembly during said extrusion being sufficient to effect bonding of the liner to the reinforcement structure.
The assembly is internally supported by a mandrel during application of the outer cover. Preferably the mandrel is formed by a pressurised fluid medium, for example air at a pressure intherange 20 to 60 p.s.i. The pressure of the fluid--medium is selected together with the pressure of the extruded cover material to ensure sufficient adhesion is obtained between the hose components.
The outer cover preferably comprises a solidifiable elastomeric material, i.e. a non-vulcanisable material, so that subsequent heating of the coated assembly to effect curing of the outer cover is not required. The cover material may be a low modulus polymer, for example polyvinyl chloride (PVC) or a thermoplastic elastomer, for example polyurethanes (PU), having a softening point of at least 1 00 C. It has been found that polyurethanes having a melt temperature of at least 200 C are particularly suitable for use as the cover material since high abrasion and cut resistance may be obtained for cover thicknesses as low as 0.01".
The liner may comprise natural or synthetic rubber. The synthetic rubber may be a vulcanisable rubber such as styrene butadiene rubber (SBR), nitrile rubber (NBR) or a thermoplastic rubber such as Hytrel (Registered Trade Mark - a block polyesterpolyether copolymer comprising the terephthalates of ethylene, tetramethylene, polyoxypropylene and polyoxytetramethylene glycols) or an ethylene vinyl acetate (EVA) block copolymer.
The reinforcement structure may be made from natural or synthetic textile material, for example polyester, rayon, polyamide, polypropylene or cotton or mixtures thereof. Alternatively the reinforcement structure may be made from a suitable nontextile material for example glass fibre or metallic material such as wire. The reinforcement structure may be knitted, woven, braided or non-woven, for example the reinforcement may comprise a spiral or helical winding.
The assembly of reinforcement structure and liner may be formed by pulling a given length of liner through a preformed reinforcement structure of corresponding length.
The liner material may adhere to the reinforcement structure to effect bonding of the liner to the reinforcement structure, for example where the liner comprises a thermoplastic rubber the heat imparted to the hose assembly during the extrusion of the outer cover may be sufficient to soften the liner material which adheres to the reinforcement structure.
More preferably bonding of the linertothe reinforcement structure is effected by an adhesive which is activated by the heat imparted to the hose assembly during extrusion of the outer cover. The adhesive may be applied to the outer surface of the liner prior to forming the assembly of inner liner and reinforcement structure. Alternatively or in addition the adhesive may be applied to the outer surface of the reinforcement structure. Where the adhesive is applied to the reinforcement structure only, for example by extrusion, the adhesive is selected to have a sufficiently low viscosity at the operating temperature that substantially complete impregnation of the interstices of the reinforcement structure occurs with the result that on subsequent activation the adhesive bonds both the liner and the cover to the reinforcement structure.
The adhesive may be a thermoplastic adhesive, for example an SBS copolymer, or a chemical adhesive, for example Daltoflex 635 (ex. I.C.I.) with an isocyanate curing agent such as Suprasec GL Cex. I.C.I.) which is activated by the temperature and pressure conditions which it experiences during extrusion of the outer cover.
Alternatively elastomeric polymer copolymers such as Grilesta D515 (ex. Grilon) are suitable dry adhesives.
According to a further aspect of the present invention we provide hose manufactured by the method according to the present invention.
The invention will now be described in more detail, by way of example only, with reference to the accompanying drawing in which the single Figure is a schematic illustration of apparatus for carrying out a method of hose manufacture according to the present invention.
A hose assembly 10 comprising an inner liner 11 of Hytrel coated with a thermoplastic adhesive 12, for example an SBS copolymer, and a tubular woven textile reinforcement jacket 13 is inflated with air to a pressure in the range 20 to 60 p.s.i. and passed through a cross-head extruder 14 where an outer cover 15 of polyurethane is applied to the jacket 13.
The thermoplastic adhesive 12 is activated by the heat imparted to the assembly during extrusion of the outer cover 15 and effects bonding of the liner 11 to the jacket 13.
On leaving the extruder 14 the covered hose assembly is passed through a cooling medium, for example water, to cool the outer cover before entering a caterpillar haul-off 16. The haul-off 16 advances the hose assembly 10 through the apparatus at a predetermined rate sufficient to ensure complete activation of the liner adhesive 12 before the covered assembly passes through the cooling medium.
From the haul-off 16 the covered assembly is passed through sets of nip rollers 17 where the assembly adopts the layflat configuration of the finished hose and then through a haul-off (not shown) from where the hose is collected and stored on a drum (not shown). The final haul-off is required to overcome drag on the hose caused by the internal pressure restricting entry into the nip.
It will be appreciated that the nip rollers 17 close the hose assembly 10 and thereby facilitate maintenance of the internal pressure in the hose assembly during application of the outer cover 15. The haul-off 16 before the nip rollers 17 may be omitted.
In a modification to the above-described method the hose assembly 10 is passed through a preheater zone 18, e.g. an array of heating devices, prior to entering the extruder 14. The degree of pre-heat is selected to ensure that the reinforcement jacket of the hose assembly 10 entering the extruder 14 is completely dry and that complete activation of the adhesive 12 occurs in the extruder 14.
In a further modification the hose assembly 10 is passed through an applicator, e.g. a T-head extruder, for applying to the reinforcement jacket 13 a thermoplastic adhesive, e.g. an SBS copolymer, which is subsequently activated by the heat imparted to the assembly during extrusion of the outer cover. The adhesive applied to the jacket 13 may be provided in addition to the adhesive 12 applied to the liner 11 and effect bonding of the cover 15 to the jacket 13.
Alternatively the step of coating the liner 11 with the adhesive 12 may be omitted and the adhesive applied to the jacket 13 selected to have a sufficiently low viscosity at the operating temperature that substantially complete impregnation of the interstices of the reinforcement jacket occursand subsequent activation of the adhesive causes the rein forcementjacket 13 to bond to both the liner 11 and cover 15. Impregnation of the reinforcement jacket 13 by the adhesive displaces the air contained in the interstices of the jacket thus improving the bonding of the liner and cover to the jacket and reducing or substantially eliminating blistering of the extruded cover by air trapped in the reinforcement jacket.
In the above-described method and modifications thereof the liner 11 is bonded to the reinforcement jacket by an adhesive. However, it will be appreci ated that the invention is not restricted to the use of adhesives but includes the possibility of forming the liner from a thermoplastic elastomer which softens sufficiently as a result of the heat imparted to the assembly during the extrusion of the cover to adhere to the reinforcement jacket under the pressure conditions and, on subsequent cooling, sets and bonds to the jacket.
It will be apparent from the foregoing that in the above-described methods and modifications thereof the liner 11 is not attached to the jacket 13 in the inflated assembly until either the adhesive, where provided has been activated or the liner material softened by passage through the extruder 14. The method of hose manufacture according to the present invention therefore combines the steps of applying the outer cover and bonding the liner to the reinforcement structure in a single stage by utilising the heat of the extrusion process to either activate the adhesive or soften the liner material. Consequently the usual step of laying out the covered assembly and inflating with steam under pressure to effect bonding of the liner to the reinforcement structure is avoided.

Claims (18)

1. A method of hose manufacture comprises providing an assembly of a tubular reinforcement structure and an inner liner of elastomeric material with an extruded outer cover of elastomeric material, the heat imparted to the hose assembly during said extrusion being sufficient to effect bonding of the liner to the reinforcement structure.
2. A method according to claim 1 wherein the liner material is a thermoplastic elastomer and the heat imparted to the hose assembly during said extrusion is sufficient to soften the liner material to effect bonding of the liner to the reinforcement structure.
3. A method according to claim 1 wherein an adhesive is applied to the hose assembly and the heat imparted to the hose assembly during said extrusion is sufficient to activate the adhesive and effect bonding of the liner to the reinforcement structure.
4. A method according to claim 3 wherein the adhesive is applied to the liner.
5. A method according to claim 3 wherein the adhesive is applied to the reinforcement structure.
6. A method according to any one of the preceding claims wherein the hose assembly is pre-heated prior to said extrusion.
7. A method according to any one of the preceding claims wherein the hose assembly is internally supported by a mandrel.
8. A method according to claim 7 wherein the mandrel comprises a pressurised fluid medium.
9. A method of hose manufacture substantially as hereinbefore described with reference to the accompanying drawing.
10. A hose manufactured by the method according to any one of claims 1 to 9.
11. A hose according to claim 10 wherein the liner material comprises natural or synthetic rubber.
12. A hose according to claim 11 wherein the liner material is a thermoplastic elastomer.
13. A hose according to any one of claims 10, 11 or 12 wherein the cover material comprises a solidifiable elastomer.
14. A hose according to any one of claims 10 to 13 wherein the reinforcement structure comprises a natural or synthetic textile material.
15. A hose according to any one of claims 10 to 13 wherein the reinforcement comprises a nontextile material.
16. A hose according to any one of claims 10 to 15 wherein the adhesive is a thermoplastic adhesive.
17. A hose according to any one of claims 10 to 15 wherein the adhesive is a chemical adhesive.
18. A hose according to any one of claims 10 to 14 wherein the adhesive is an elastomeric polyester copolymer.
GB8018094A 1979-06-08 1980-06-03 Manufacture of reinforced hose Expired GB2052360B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8018094A GB2052360B (en) 1979-06-08 1980-06-03 Manufacture of reinforced hose

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB7920424 1979-06-08
GB8018094A GB2052360B (en) 1979-06-08 1980-06-03 Manufacture of reinforced hose

Publications (2)

Publication Number Publication Date
GB2052360A true GB2052360A (en) 1981-01-28
GB2052360B GB2052360B (en) 1983-02-16

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB8018094A Expired GB2052360B (en) 1979-06-08 1980-06-03 Manufacture of reinforced hose

Country Status (1)

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GB (1) GB2052360B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0099999A2 (en) * 1982-07-21 1984-02-08 Christoph Vohrer Process for producing a reinforced hose
US5723199A (en) * 1995-01-31 1998-03-03 Reddiplex Group Plc Method of extruding two or more materials
EP1475206A1 (en) * 2003-05-06 2004-11-10 Veritas Ag Manufacture of vulcanized hoses

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0099999A2 (en) * 1982-07-21 1984-02-08 Christoph Vohrer Process for producing a reinforced hose
EP0099999A3 (en) * 1982-07-21 1985-01-16 Christoph Vohrer Process for producing a reinforced hose
US5723199A (en) * 1995-01-31 1998-03-03 Reddiplex Group Plc Method of extruding two or more materials
EP1475206A1 (en) * 2003-05-06 2004-11-10 Veritas Ag Manufacture of vulcanized hoses

Also Published As

Publication number Publication date
GB2052360B (en) 1983-02-16

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee