CA1043716A - Composite reinforced hose - Google Patents
Composite reinforced hoseInfo
- Publication number
- CA1043716A CA1043716A CA217,401A CA217401A CA1043716A CA 1043716 A CA1043716 A CA 1043716A CA 217401 A CA217401 A CA 217401A CA 1043716 A CA1043716 A CA 1043716A
- Authority
- CA
- Canada
- Prior art keywords
- core tube
- hose
- composite reinforced
- nylon
- layer
- 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
Links
Classifications
-
- 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
- F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
- F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
- F16L11/085—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more braided layers
- F16L11/086—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more braided layers two layers
-
- 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
- F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
- F16L11/12—Hoses, i.e. flexible pipes made of rubber or flexible plastics with arrangements for particular purposes, e.g. specially profiled, with protecting layer, heated, electrically conducting
- F16L11/127—Hoses, i.e. flexible pipes made of rubber or flexible plastics with arrangements for particular purposes, e.g. specially profiled, with protecting layer, heated, electrically conducting electrically conducting
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Laminated Bodies (AREA)
Abstract
COMPOSITE REINFORCED HOSE
Abstract of the Disclosure A composite reinforced hose fox conveying fluids under pressure is provided with a core tube coextruded from at least two thermoplastic synthetic resins having different physical properties and melt fused together in layers relative to each other to provide maximum benefit from the more desirable properties of each of the resins, a fibrous reinforcing material about the core tube and a protective synthetic resinous sheath over the fibrous material.
Abstract of the Disclosure A composite reinforced hose fox conveying fluids under pressure is provided with a core tube coextruded from at least two thermoplastic synthetic resins having different physical properties and melt fused together in layers relative to each other to provide maximum benefit from the more desirable properties of each of the resins, a fibrous reinforcing material about the core tube and a protective synthetic resinous sheath over the fibrous material.
Description
37~6 This invention relates generally to composite rein-forced hose adapted to convey fluids under pressure and more particularly to an improved hose of this type of construction which has certain advantageous physical properties for use in a particular application without substantial compromise of other ~-desirable physical properties.
Composite hoses are used extensively to conduct fluids ~ ~
under pressure. The conventional flexible hydraulic hose has a ~ ~ -core tube extruded from a single synthetic resin, a fibrous reinforcing material about the core tube to support it against radial expansion and elongation and a synthetic resinous pro-tective sheath covering the fibrous material. Composite hoses of this type are disclosed, for example, in U.S. Patents 3,06~,241;
3,33~,447; 3,334,165; 3,251,381; 3,116,760 and 3,722,550. Such ~;
composite hoses sho~ld be flexible, substantially kink resistant and also have a burst strength which permits their use with fluids under relatively high pressure. Moreover, the hose should be sub-stantially resistant to chemical attack by the fluid carried there-by. As indicated by the disclosures in the above patents, various kinds of synthetic resins have been proposed for making the dif-ferent components of the hose. The choice of synthetic resin used for making the core tube, for example, may vary from one hose to another depending upon the relative importance of the physical properties. For example, it may be desirable to select a resin like nylon 11 for the core tube where resistance to chemical attack by the fluid carried by the hose is essential. Unfortunately, hoses having a nylon 11 core tube are not as flexible as hoses : .. ,, - . . . : - . . .
3'7~
having a core tube made from another resin such as polyurethane.
However, polyurethane is not as resistant to attack by some fluids as nylon. So in deciding between a nylon and polyurethane for a core tube, it is necessary to compromise one property in favor of another. In some hoses it is desirable to bond the core tube to `
the fibrous reinforcing material. Polyurethane is advantageous for the core tube of the bonded hose because it can be treated with a solvent to soften the surface of the core tube to form an ad- -hesive which bonds the fibrous strands to the core tube. The polyurethane core tube can be used only in those hoses, however, where the polyurethane provides sufficient chemical resistance to permit the hose to carry the fluid involved. Hence, with the ~
prior art hoses it has been the practice to select a core tube -which has the most necessary properties and to tolerate a compro-mise in other somewhat less important properties. Such a procedure of course can not provide a hose having optimum properties ~or many industrial applications.
It is therefore an object of this invention to provide an improved composite reinforced hose for conveying fluids under pressure which has those properties most necessary ~or proper functioning without a major sacrifice in some of its other proper-ties. A more specific object of the invention is to provide a composite reinforced hose adapted to convey fluids under pressure ~ -having a structure which parmits a greater latitude in selecting the various components of the hose to meet the various conditions to which the hose is li~ely to be subjected. Still another object of the invention is to provide a composite hose which combines -
Composite hoses are used extensively to conduct fluids ~ ~
under pressure. The conventional flexible hydraulic hose has a ~ ~ -core tube extruded from a single synthetic resin, a fibrous reinforcing material about the core tube to support it against radial expansion and elongation and a synthetic resinous pro-tective sheath covering the fibrous material. Composite hoses of this type are disclosed, for example, in U.S. Patents 3,06~,241;
3,33~,447; 3,334,165; 3,251,381; 3,116,760 and 3,722,550. Such ~;
composite hoses sho~ld be flexible, substantially kink resistant and also have a burst strength which permits their use with fluids under relatively high pressure. Moreover, the hose should be sub-stantially resistant to chemical attack by the fluid carried there-by. As indicated by the disclosures in the above patents, various kinds of synthetic resins have been proposed for making the dif-ferent components of the hose. The choice of synthetic resin used for making the core tube, for example, may vary from one hose to another depending upon the relative importance of the physical properties. For example, it may be desirable to select a resin like nylon 11 for the core tube where resistance to chemical attack by the fluid carried by the hose is essential. Unfortunately, hoses having a nylon 11 core tube are not as flexible as hoses : .. ,, - . . . : - . . .
3'7~
having a core tube made from another resin such as polyurethane.
However, polyurethane is not as resistant to attack by some fluids as nylon. So in deciding between a nylon and polyurethane for a core tube, it is necessary to compromise one property in favor of another. In some hoses it is desirable to bond the core tube to `
the fibrous reinforcing material. Polyurethane is advantageous for the core tube of the bonded hose because it can be treated with a solvent to soften the surface of the core tube to form an ad- -hesive which bonds the fibrous strands to the core tube. The polyurethane core tube can be used only in those hoses, however, where the polyurethane provides sufficient chemical resistance to permit the hose to carry the fluid involved. Hence, with the ~
prior art hoses it has been the practice to select a core tube -which has the most necessary properties and to tolerate a compro-mise in other somewhat less important properties. Such a procedure of course can not provide a hose having optimum properties ~or many industrial applications.
It is therefore an object of this invention to provide an improved composite reinforced hose for conveying fluids under pressure which has those properties most necessary ~or proper functioning without a major sacrifice in some of its other proper-ties. A more specific object of the invention is to provide a composite reinforced hose adapted to convey fluids under pressure ~ -having a structure which parmits a greater latitude in selecting the various components of the hose to meet the various conditions to which the hose is li~ely to be subjected. Still another object of the invention is to provide a composite hose which combines -
- 2 -.
371~ ~
optimum flexibility~ kink resistance, resistance to chemical attack and other desirable properties. A still further object of the invention is to provide a composite reinforced hose having a core tube which has the better properties of a plurality of thermoplastic synthetic resins without substantial compromise :
of other properties of the tube.
Other objects will become apparent from the following description with reference to the accompanying drawing wherein Fig~re 1 is a fragmentary side elevation, partially :~
cut away, of one embodiment of the invention; and ~ .
Figure 2 is a cross-section taken along the line 2-2 of Figure 1.
The foregoing ob~ects and others are accomplished in accordance with this invention, generally speaking, by pro-viding a composite reinforced hose having a core tube shaped .
from at least two layers of synthetic thermoplastic resin which have different physical properties melt fused directly together at an interface into a wall which acts as a unitary structure, one or more layers of a fibrous reinforcing material disposed ~;
about the core tube and a protective synthetic resinous sheathdisposed about the fibrous reinforcing material~
The invention broadly contemplates composite reinforced hose having a core tube of two or more layers of synthetic resin ~ ~:
having different physical properties fused together into a single wall which will not separate into layers under the conditions to ~.
which the hose is subjected while functioning as a hydraulic hose, any suitable fibrous reinforcing material abo~t the core tube and
371~ ~
optimum flexibility~ kink resistance, resistance to chemical attack and other desirable properties. A still further object of the invention is to provide a composite reinforced hose having a core tube which has the better properties of a plurality of thermoplastic synthetic resins without substantial compromise :
of other properties of the tube.
Other objects will become apparent from the following description with reference to the accompanying drawing wherein Fig~re 1 is a fragmentary side elevation, partially :~
cut away, of one embodiment of the invention; and ~ .
Figure 2 is a cross-section taken along the line 2-2 of Figure 1.
The foregoing ob~ects and others are accomplished in accordance with this invention, generally speaking, by pro-viding a composite reinforced hose having a core tube shaped .
from at least two layers of synthetic thermoplastic resin which have different physical properties melt fused directly together at an interface into a wall which acts as a unitary structure, one or more layers of a fibrous reinforcing material disposed ~;
about the core tube and a protective synthetic resinous sheathdisposed about the fibrous reinforcing material~
The invention broadly contemplates composite reinforced hose having a core tube of two or more layers of synthetic resin ~ ~:
having different physical properties fused together into a single wall which will not separate into layers under the conditions to ~.
which the hose is subjected while functioning as a hydraulic hose, any suitable fibrous reinforcing material abo~t the core tube and
- 3 -.. . . ..
an external protective sheath of any suikable thermoplastic polymer.
The invention permits the manufacture of a composite reinforced hose having some particularly desirable property -without substantial compromise of other desirable properties.
For example, a substantially chemically resistant polymer such as nylon may be chosen for the inside layer of the core tube wall and a layer of a more flexible polymer such as an elasto-meric polyurethane may be fused thereto as the outer surface to provide improved flexibility and kink resistance. The outer layer may be shaped from a resin from which an adhesive can be made with a polar solvent to adhesively bond the core tube to the reinforciny material and to improve the strength of the hose. In such a hose, the relative thickness of the nylon and polyurethane may be varied to further modify the properties of the hose. In another embodiment of the invention the inner layer of the core tube wall may be a solvent resistant thermoplastic polymer fused to an outer layer which forms the external surface of the core tube and has particles of a conductive material such as carbon black dispersed therein to provide a hose for use in an airless high pressure paint spray system. Hoses in which the core tube ~
has a substantially non-porous inner portion fused to a foam ~ -plastic or porous outer portion may also be provided in accord-ance with the invention.
The core tube may be fabricated by any suitable pro- ;
cess which will produce melt fusion of two different layers of synthetic thermoplastic resins together to the extent that the ' ~'' ' . . .. .
~37~
two layers will not separate at the interface under elongation and other conditions to which the hose will be exposed. The most practical method of ma~ing the core tube is to supply two dif-ferent synthetic thermoplastic resins or two different types o~
the same thermoplastic resin to a single extrusion head from -different extruders operating under conditions whereby the resin which will be the inner portion of the core tube is still molten when the molten resin for the other portion of the core tube wall is applied thereover and the two molten synthetic resins are ex~
truded through the same extrusion die.
It has been found that two layers ofse~eGte~hermoplastic synthetic resin will melt fuse together along the interface and become so firmly bonded together that the core tube will not delaminate in a hose used to convey fluids under high pressures ~ -even if the physical properties of the two layers are significantly different. For example, nylon ll and a thermoplastic polyurethane ~;
will melt fuse to~ether in accordance with the process of the in~
vention. ~Ience, the invention contemplates a hose having a core tube with a layer of nylon ll melt fused to a layer of thermoplastic ~
substantially non-porous polyurethane. Usually, the nylon 11 layer -will be the innermost layer because of its chemical resistance.
The polyurethane layer imparts flexibility to the hose and may also be used for making an adhesive to bond the core tube to the fibrous reinforcing layer so it is usually disposed on the out-side of the core tube.
Nylon 12 and thermoplastic polyurethane layers will also melt fuse together. Because of its chemical resistance the nylon 12 layer may be used as the inner layer of a core tube with a thermoplastic polyurethane outer layer.
lV~37~6 The invention also provides composite reinforced hoses having a core tube of two or more layers of synthetic resin of the same general chemical composition but modified to provide dif~erent physical properties. For example, a relatively hard thermoplastic polyurethane having a hardness of Shore D 50 to 60 and a relatively soft thermoplastic polyurethane having a h~rdness of Shore A 80 to 95 may be coextruded to form a core tube. The harder thermoplastic polyurethane has better chemical resistance than the softer one so the harder one is usually the inner layer of the core tube. The presence of the layer of softer polyurethane improves the flexibility of the hose.
Still another hose provided by the invention has a core tube in which the innermost layer is Hytrel having a hardness of about Shore D 55 and an outer layer of Hytrel having a hardness of about Shore A 90. Such a hose has advantageous physical proper-ties at elevated temperatures.
In another embodiment of the invention, a breathing hose which must not only be flexible and kink resistant but must also be capable of carrying a fluid without contamination by the core ~-tube is provided with a core tube having a layer of unplasticized nylon 11 on its inside and a layer of plasticized nylon ll on its ` -~
outside.
A hose suitable for conducting paint under high pressure may bs provided in accordance with the invention with a core tube having an inner layer of nylon 11 or nylon 12 and a layer of thermoplastic polyurethane containing carbon black particles melt fused to the nylon 11 or 12 layer. The nylon layer provides , .
~ 371~
solvent resistance for conveying the paint in the core tube and the polyurethane containing carbon black particles is a semi-conductor for conducting static electric charges to ground.
In a variation of a hose of this type the inner layer may be nylon 11 and the outer layer nylon 11 having carbon black dispersed therein.
The core tube may be adhesively bonded to the surface of the reinforcing material by the application of an adhesive material or by activating the surface of the core tube ~ith a `
solvent or softening agent to form an adhesive ln situ from the resin on the outer surface of the core tube. For example, a polyurethane surface of a core tube may be activated by wetting it with a suitable polar solvent such as, for example, N-methyl pyrrolidone or the like. The reinforcing fibrous material is then applied under tension about the wet core tube whereby the strands of reinforcing material become embedded and partially encapsulated by the softened core tube material. In this way, the fibrous reinforcing layer becomes bonded to the core tube and the strength of the hose is improved.
"Hytrel'i is a synthetic resin sold by E.I. duPont de Nemours and Company. "Hytrel" is a segmented co-polyester and is described in U.S. Patent 3,766,1~6.
It has been found that simultaneously coextruded prop~rly selected synthetic thermoplastic resins of different physical properties will become bonded together by melt fusion and that an intermediate adhesive is not necessary. For example, * Trade Mark ~", ~ ,. .
' .
. .
~~43~
nylon will fuse to a thermoplastic elastomeric polyurethane if the two molten synthetic resins are fed separately to an ~ -extrusion head and coextruded one over the other while still molten. In those instances where one layer of the core tube is difficult to melt fuse to another layer an intermediate layer of a third synthetic resin which will melt fuse to both layers may be interposed therebetween.
It has been unexpectedly discovered that the core tube having two or more la~ers of synthetic thermoplastic resins of different physical properties has an elongation at break which is about equal to that of the more flexible resin instead of an average of the two elongations or near that of the resin having the lower elongation. In other words, the melt fused layers remain melt fused together and break together at the break point of the resin having the greater elongation.
For example, a core tube was prepared by extruding a layer of nylon 11 0.020 inch thick and while the nylon 11 was still molten extruding a layer of thermoplastic polyurethane 0.025 ~ `
inch thick over the nylon 11 layer. The two layers were melt ~ -20 fused together. -~-With the same apparatus, a core tube of a single layer of the same nylon 11 havin~ a wall-thickness of 0.020 inch was extruded and another core tube having a wall-thickness of 0.025 inch was extruded from the same polyurethane as used to make the dual ext~uded tube.
Test samples were cut from all three samples and the elongation at b~eak was determined. Surprisingly, the elongation : .
7~
at break of the laminated core tube was comparable to that of the polyuretha~e core tube. The following experimental results were obtained: -n = number of samples tested X = average elongation, percent S = standard deviation of population, percent CI = 95 percent con~idence interval, percent Composite Polyurethane Nylon 11 Tube The confidence interval tells us that there is only one chance in twenty that the total population average lies outside this range. The confidence interval for the composite tube elonga-tion is substantially higher than the range for the all-nylon tube, while it overlaps the range for the all-urethane tube.
The elongation at break of the composi~.e tube is at least 9.9 ;
percent (and probably 20.5 percent) better than the elongation of the all-nylon 11 tube extruded under the same conditions.
Referring now to the drawing, a composite hose 10 is ;
illustrated in Figures 1 and 2. Compasite hose 10 has a core tube 17 formed by the simultaneous coextrusion of a layer of nylon 11 about 0.020 inch thick and a thermoplastic elastomeric polyurethane 12 such as "Pellethane" 90 A outer layer about 0.025 inch thick. The two synthetic resins become fused together at the interface to form a core tube which will not delaminate when the hose 10 is used for conveying a fluid under pressure. ;
... . ~
:~.V~3~1~
The outer surface of polyurethane o~ core tube 17 is wet with N-methyl pyrrolidone to form in situ a gel-like material 13 on the surface thereof. A reinforcing layer 14 of poly(ethylene terephthalate)ester filaments is braided under tension around the core tube while the surface of core tube 17 is activated by the solvent. The filaments become embedded and partially encapsulated in the surface of the core tube 17 forming an elastomeric bond of the fibrous reinforcing material with the core tube. A second reinforcing layer 15 may be applied over layer 14. A protective polyurethane sheath is applied over fibrous reinforcing layer 15 by extrusion of a thermoplastic elastomeric polyurethane thereover.
Any of the other core tubes disclosed as suitable herein may be substituted in the foregoiny embodiment of the ;
invention for core tube 17 and the core tube 17 may or may not -~
be bonded to the reinforcing layer dep~nding upon the particular requirements of the hose.
The polyurethane sheath 16 and the polyurethane 12 of core tube 17 may be extruded from any suitable thermoplastic polyurethane such as the old one sold under the trademark "Pelle-thane" by the Up~ohn Company. The polyurethane disclosed in U.S.
Patents 3,116,760 and 3,722,550 and disclosed in the book by Saunders and Frisch, entitled "Polyurethanes: Chemistry and Technology", published by Interscience Publishers, copyright 1964 may also be used. Reaction products of poly(tetramethylene ether) glycol, suitable chain extender such as 1,4 butane diol, and 4,4' diphenylmethane diisocyanate and polyurethanes prepared by reacting an inner ester such as poly (s-caprolactone) ester and a suitable chai~ extender such as 1,4 butane diol with an aromatic diisocyanate such as ' . 5 ' , . . ' ' " ' ~ : , '' ' ' . ', :' ' ',' ~ ' , 7~
an external protective sheath of any suikable thermoplastic polymer.
The invention permits the manufacture of a composite reinforced hose having some particularly desirable property -without substantial compromise of other desirable properties.
For example, a substantially chemically resistant polymer such as nylon may be chosen for the inside layer of the core tube wall and a layer of a more flexible polymer such as an elasto-meric polyurethane may be fused thereto as the outer surface to provide improved flexibility and kink resistance. The outer layer may be shaped from a resin from which an adhesive can be made with a polar solvent to adhesively bond the core tube to the reinforciny material and to improve the strength of the hose. In such a hose, the relative thickness of the nylon and polyurethane may be varied to further modify the properties of the hose. In another embodiment of the invention the inner layer of the core tube wall may be a solvent resistant thermoplastic polymer fused to an outer layer which forms the external surface of the core tube and has particles of a conductive material such as carbon black dispersed therein to provide a hose for use in an airless high pressure paint spray system. Hoses in which the core tube ~
has a substantially non-porous inner portion fused to a foam ~ -plastic or porous outer portion may also be provided in accord-ance with the invention.
The core tube may be fabricated by any suitable pro- ;
cess which will produce melt fusion of two different layers of synthetic thermoplastic resins together to the extent that the ' ~'' ' . . .. .
~37~
two layers will not separate at the interface under elongation and other conditions to which the hose will be exposed. The most practical method of ma~ing the core tube is to supply two dif-ferent synthetic thermoplastic resins or two different types o~
the same thermoplastic resin to a single extrusion head from -different extruders operating under conditions whereby the resin which will be the inner portion of the core tube is still molten when the molten resin for the other portion of the core tube wall is applied thereover and the two molten synthetic resins are ex~
truded through the same extrusion die.
It has been found that two layers ofse~eGte~hermoplastic synthetic resin will melt fuse together along the interface and become so firmly bonded together that the core tube will not delaminate in a hose used to convey fluids under high pressures ~ -even if the physical properties of the two layers are significantly different. For example, nylon ll and a thermoplastic polyurethane ~;
will melt fuse to~ether in accordance with the process of the in~
vention. ~Ience, the invention contemplates a hose having a core tube with a layer of nylon ll melt fused to a layer of thermoplastic ~
substantially non-porous polyurethane. Usually, the nylon 11 layer -will be the innermost layer because of its chemical resistance.
The polyurethane layer imparts flexibility to the hose and may also be used for making an adhesive to bond the core tube to the fibrous reinforcing layer so it is usually disposed on the out-side of the core tube.
Nylon 12 and thermoplastic polyurethane layers will also melt fuse together. Because of its chemical resistance the nylon 12 layer may be used as the inner layer of a core tube with a thermoplastic polyurethane outer layer.
lV~37~6 The invention also provides composite reinforced hoses having a core tube of two or more layers of synthetic resin of the same general chemical composition but modified to provide dif~erent physical properties. For example, a relatively hard thermoplastic polyurethane having a hardness of Shore D 50 to 60 and a relatively soft thermoplastic polyurethane having a h~rdness of Shore A 80 to 95 may be coextruded to form a core tube. The harder thermoplastic polyurethane has better chemical resistance than the softer one so the harder one is usually the inner layer of the core tube. The presence of the layer of softer polyurethane improves the flexibility of the hose.
Still another hose provided by the invention has a core tube in which the innermost layer is Hytrel having a hardness of about Shore D 55 and an outer layer of Hytrel having a hardness of about Shore A 90. Such a hose has advantageous physical proper-ties at elevated temperatures.
In another embodiment of the invention, a breathing hose which must not only be flexible and kink resistant but must also be capable of carrying a fluid without contamination by the core ~-tube is provided with a core tube having a layer of unplasticized nylon 11 on its inside and a layer of plasticized nylon ll on its ` -~
outside.
A hose suitable for conducting paint under high pressure may bs provided in accordance with the invention with a core tube having an inner layer of nylon 11 or nylon 12 and a layer of thermoplastic polyurethane containing carbon black particles melt fused to the nylon 11 or 12 layer. The nylon layer provides , .
~ 371~
solvent resistance for conveying the paint in the core tube and the polyurethane containing carbon black particles is a semi-conductor for conducting static electric charges to ground.
In a variation of a hose of this type the inner layer may be nylon 11 and the outer layer nylon 11 having carbon black dispersed therein.
The core tube may be adhesively bonded to the surface of the reinforcing material by the application of an adhesive material or by activating the surface of the core tube ~ith a `
solvent or softening agent to form an adhesive ln situ from the resin on the outer surface of the core tube. For example, a polyurethane surface of a core tube may be activated by wetting it with a suitable polar solvent such as, for example, N-methyl pyrrolidone or the like. The reinforcing fibrous material is then applied under tension about the wet core tube whereby the strands of reinforcing material become embedded and partially encapsulated by the softened core tube material. In this way, the fibrous reinforcing layer becomes bonded to the core tube and the strength of the hose is improved.
"Hytrel'i is a synthetic resin sold by E.I. duPont de Nemours and Company. "Hytrel" is a segmented co-polyester and is described in U.S. Patent 3,766,1~6.
It has been found that simultaneously coextruded prop~rly selected synthetic thermoplastic resins of different physical properties will become bonded together by melt fusion and that an intermediate adhesive is not necessary. For example, * Trade Mark ~", ~ ,. .
' .
. .
~~43~
nylon will fuse to a thermoplastic elastomeric polyurethane if the two molten synthetic resins are fed separately to an ~ -extrusion head and coextruded one over the other while still molten. In those instances where one layer of the core tube is difficult to melt fuse to another layer an intermediate layer of a third synthetic resin which will melt fuse to both layers may be interposed therebetween.
It has been unexpectedly discovered that the core tube having two or more la~ers of synthetic thermoplastic resins of different physical properties has an elongation at break which is about equal to that of the more flexible resin instead of an average of the two elongations or near that of the resin having the lower elongation. In other words, the melt fused layers remain melt fused together and break together at the break point of the resin having the greater elongation.
For example, a core tube was prepared by extruding a layer of nylon 11 0.020 inch thick and while the nylon 11 was still molten extruding a layer of thermoplastic polyurethane 0.025 ~ `
inch thick over the nylon 11 layer. The two layers were melt ~ -20 fused together. -~-With the same apparatus, a core tube of a single layer of the same nylon 11 havin~ a wall-thickness of 0.020 inch was extruded and another core tube having a wall-thickness of 0.025 inch was extruded from the same polyurethane as used to make the dual ext~uded tube.
Test samples were cut from all three samples and the elongation at b~eak was determined. Surprisingly, the elongation : .
7~
at break of the laminated core tube was comparable to that of the polyuretha~e core tube. The following experimental results were obtained: -n = number of samples tested X = average elongation, percent S = standard deviation of population, percent CI = 95 percent con~idence interval, percent Composite Polyurethane Nylon 11 Tube The confidence interval tells us that there is only one chance in twenty that the total population average lies outside this range. The confidence interval for the composite tube elonga-tion is substantially higher than the range for the all-nylon tube, while it overlaps the range for the all-urethane tube.
The elongation at break of the composi~.e tube is at least 9.9 ;
percent (and probably 20.5 percent) better than the elongation of the all-nylon 11 tube extruded under the same conditions.
Referring now to the drawing, a composite hose 10 is ;
illustrated in Figures 1 and 2. Compasite hose 10 has a core tube 17 formed by the simultaneous coextrusion of a layer of nylon 11 about 0.020 inch thick and a thermoplastic elastomeric polyurethane 12 such as "Pellethane" 90 A outer layer about 0.025 inch thick. The two synthetic resins become fused together at the interface to form a core tube which will not delaminate when the hose 10 is used for conveying a fluid under pressure. ;
... . ~
:~.V~3~1~
The outer surface of polyurethane o~ core tube 17 is wet with N-methyl pyrrolidone to form in situ a gel-like material 13 on the surface thereof. A reinforcing layer 14 of poly(ethylene terephthalate)ester filaments is braided under tension around the core tube while the surface of core tube 17 is activated by the solvent. The filaments become embedded and partially encapsulated in the surface of the core tube 17 forming an elastomeric bond of the fibrous reinforcing material with the core tube. A second reinforcing layer 15 may be applied over layer 14. A protective polyurethane sheath is applied over fibrous reinforcing layer 15 by extrusion of a thermoplastic elastomeric polyurethane thereover.
Any of the other core tubes disclosed as suitable herein may be substituted in the foregoiny embodiment of the ;
invention for core tube 17 and the core tube 17 may or may not -~
be bonded to the reinforcing layer dep~nding upon the particular requirements of the hose.
The polyurethane sheath 16 and the polyurethane 12 of core tube 17 may be extruded from any suitable thermoplastic polyurethane such as the old one sold under the trademark "Pelle-thane" by the Up~ohn Company. The polyurethane disclosed in U.S.
Patents 3,116,760 and 3,722,550 and disclosed in the book by Saunders and Frisch, entitled "Polyurethanes: Chemistry and Technology", published by Interscience Publishers, copyright 1964 may also be used. Reaction products of poly(tetramethylene ether) glycol, suitable chain extender such as 1,4 butane diol, and 4,4' diphenylmethane diisocyanate and polyurethanes prepared by reacting an inner ester such as poly (s-caprolactone) ester and a suitable chai~ extender such as 1,4 butane diol with an aromatic diisocyanate such as ' . 5 ' , . . ' ' " ' ~ : , '' ' ' . ', :' ' ',' ~ ' , 7~
4',4'-diphenylmethane diisocyanate are preferred. The sheath 16 may also be extruded from any other suitable synthetic resin such as, for example, nylon in some embodiments of the invention.
The fibrous reinforcing material may be formed by braiding or by helically winding filaments of any suitable synthetic resinous material, such as, for example, a poly (alkylene terephthlate)ester or nylon, such as nylon 6 or nylon 66. Suitable nylon fibrous reinforcin~ material is dis- ~
10 closed in U.S. Patent 3,334,164 while suitable poly(alkylene -terephthalate~ester fibrous reinforcing material is disclosed in U.S. Patent 3,062,241. Such fibers have a tenacity at room temperature of about 7 to about 11 grams per denier and an elongation at break of about 9% to about 17%. In a preferred embodiment of the invention, the hose is provided with a reinforcing layer of braided or helically wound filaments having a tenacity at room temperature of at least 12 grams per denier and up to about 2S grams per denier and an elongation at break of from about 29~ to about 7%. An aromatic polyamide fiber 20 marketed by E.I. duPont de Nemours & Co. under the trademark "Kevlar" and known variously in the art as "Fiber B" and as an aramide filament may be used. Suitable reinforcing material ;~
containing synthetic aromatic polyamide filaments is disclosed in our copending application No. 217,239 filed January 2, 1975.
A fibrous reinforcing material of aromatic polyamide fibers is preferred for composite hoses having a high burst strength.
~ ' .: . . . :
:~ .
7~1 f;
The core tube can be shaped by extrusion with any suitable extrusion apparatus having a separate extruder ~or feeding each synthetic thermoplastic resin to a single extrusion head.
It is apparent from the foregoin~ that the composite reinforced hose provided by the invention has the advantage over prior art hoses that a synthetic resin can be placed in the core tube where its particular physical properties are most needed -~
without materially compromising other properties of the hose.
10 For example, the synthetic resin for the inner layer of the core -tube may be chosen for its chemical resistance or to provide the hose with both chemical resistance and tensile strength while a more flexible synthetic resin is chosen for the outer layer of the core tube to maintain overall flexibility. The , ~-invention also permits variation of the thicknesses of the layers -of the core tube to provide the hose with a particular property.
The layers of the core tube may also be chosen to provide novel combinations of properties such as chemical resistance with ~-~
electrical conductivity or insulation. The cost of the hose can also be reduced by using only a relatively thin layer of the more costly but desirable synthetic resin only on that sur~ace of the core tube where it is needed. It is also possible to pro- ~ ;
vide a substantially non-porous synthetic resin layer in combina-tion with a foam layer such as a polyurethane foam layer. By proper selection of the combination of layers of resins used in the core tube, it is also possible to provide for kink resistance in combination with a reinforcing material bonded to the sheath. ;
... . .
3~l6 Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without de-parting from the spirit and scope of the invention except as it may be limited by the claims. -: . ,
The fibrous reinforcing material may be formed by braiding or by helically winding filaments of any suitable synthetic resinous material, such as, for example, a poly (alkylene terephthlate)ester or nylon, such as nylon 6 or nylon 66. Suitable nylon fibrous reinforcin~ material is dis- ~
10 closed in U.S. Patent 3,334,164 while suitable poly(alkylene -terephthalate~ester fibrous reinforcing material is disclosed in U.S. Patent 3,062,241. Such fibers have a tenacity at room temperature of about 7 to about 11 grams per denier and an elongation at break of about 9% to about 17%. In a preferred embodiment of the invention, the hose is provided with a reinforcing layer of braided or helically wound filaments having a tenacity at room temperature of at least 12 grams per denier and up to about 2S grams per denier and an elongation at break of from about 29~ to about 7%. An aromatic polyamide fiber 20 marketed by E.I. duPont de Nemours & Co. under the trademark "Kevlar" and known variously in the art as "Fiber B" and as an aramide filament may be used. Suitable reinforcing material ;~
containing synthetic aromatic polyamide filaments is disclosed in our copending application No. 217,239 filed January 2, 1975.
A fibrous reinforcing material of aromatic polyamide fibers is preferred for composite hoses having a high burst strength.
~ ' .: . . . :
:~ .
7~1 f;
The core tube can be shaped by extrusion with any suitable extrusion apparatus having a separate extruder ~or feeding each synthetic thermoplastic resin to a single extrusion head.
It is apparent from the foregoin~ that the composite reinforced hose provided by the invention has the advantage over prior art hoses that a synthetic resin can be placed in the core tube where its particular physical properties are most needed -~
without materially compromising other properties of the hose.
10 For example, the synthetic resin for the inner layer of the core -tube may be chosen for its chemical resistance or to provide the hose with both chemical resistance and tensile strength while a more flexible synthetic resin is chosen for the outer layer of the core tube to maintain overall flexibility. The , ~-invention also permits variation of the thicknesses of the layers -of the core tube to provide the hose with a particular property.
The layers of the core tube may also be chosen to provide novel combinations of properties such as chemical resistance with ~-~
electrical conductivity or insulation. The cost of the hose can also be reduced by using only a relatively thin layer of the more costly but desirable synthetic resin only on that sur~ace of the core tube where it is needed. It is also possible to pro- ~ ;
vide a substantially non-porous synthetic resin layer in combina-tion with a foam layer such as a polyurethane foam layer. By proper selection of the combination of layers of resins used in the core tube, it is also possible to provide for kink resistance in combination with a reinforcing material bonded to the sheath. ;
... . .
3~l6 Although the invention has been described in detail for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without de-parting from the spirit and scope of the invention except as it may be limited by the claims. -: . ,
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A composite reinforced hose for conveying fluids under pressure comprising a core tube, a fibrous reinforcing material about the core tube and a protective sheath over the fibrous material, said core tube having been coextruded from at least two thermoplastic synthetic resins having different properties and melt fused directly together at the interface of adjacent layers of said different resins to form a wall which acts as a unitary structure to provide a hose wherein the said thermoplastic synthetic resins are disposed in the core tube in layers relative to each other to provide maximum benefit from the more desirable properties of each of the synthetic resins.
2. The composite reinforced hose of Claim 1 wherein the said layers of the core tube are disposed to provide flexi-bility and kink resistance in combination with resistance against attack by fluid conveyed therethrough.
3. The composite reinforced hose of Claim 1 wherein the core tube has an innermost layer which adapts it to convey fluids without contamination of the fluid.
4. The composite reinforced hose of Claim 1 wherein the core tube has an innermost layer which resists chemical attack by fluid carried thereby and an outermost layer providing a means for bonding the reinforcing material to the core tube.
5. The composite reinforced hose of Claim 1 wherein the core tube has only two layers and the inner layer is nylon and the outer layer is thermoplastic polyurethane.
6. The composite reinforced hose of Claim 5 wherein the fibrous reinforcing material is nylon 6, nylon 66, poly-(ethylene terephthalate)ester or an aromatic polyamide.
7. The composite hose of Claim 6 wherein the sheath is a thermoplastic polyurethane.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US46961174A | 1974-05-13 | 1974-05-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1043716A true CA1043716A (en) | 1978-12-05 |
Family
ID=23864425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA217,401A Expired CA1043716A (en) | 1974-05-13 | 1975-01-06 | Composite reinforced hose |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5410367B2 (en) |
| BE (1) | BE825081A (en) |
| CA (1) | CA1043716A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53148320U (en) * | 1977-04-28 | 1978-11-22 | ||
| JPS5650223Y2 (en) * | 1977-09-07 | 1981-11-24 | ||
| US4196464A (en) * | 1978-02-23 | 1980-04-01 | Eaton Corporation | Semi-conductive layer-containing reinforced pressure hose and method of making same |
| JPS54128915U (en) * | 1978-02-28 | 1979-09-07 | ||
| JP4712423B2 (en) * | 2005-04-05 | 2011-06-29 | 三桜工業株式会社 | Quick connector |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4425110Y1 (en) * | 1966-07-19 | 1969-10-22 | ||
| JPS475966U (en) * | 1971-02-13 | 1972-09-20 | ||
| JPS4721214U (en) * | 1971-02-27 | 1972-11-09 | ||
| JPS497938U (en) * | 1972-04-21 | 1974-01-23 | ||
| JPS5114360A (en) * | 1974-07-26 | 1976-02-04 | Yamato Scale Co Ltd | HIZUMIKEN SHUTSUSOCHI |
-
1975
- 1975-01-06 CA CA217,401A patent/CA1043716A/en not_active Expired
- 1975-01-28 JP JP1105175A patent/JPS5410367B2/ja not_active Expired
- 1975-01-31 BE BE152969A patent/BE825081A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5410367B2 (en) | 1979-05-04 |
| JPS50146924A (en) | 1975-11-25 |
| BE825081A (en) | 1975-05-15 |
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