JPH0125698B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improved method of manufacturing reinforced tubular articles such as hoses.

According to the present invention, a method of manufacturing a reinforced tubular article comprises applying at least one layer of material reinforcing the article to a tube of polymeric material forming the inner liner of the article and applying a liquid elastomer to this layer. thoroughly impregnating the forming reaction mixture.

The method of the invention is particularly useful when the inner liner is provided with multiple (at least two) reinforcing layers and these reinforcing layers are impregnated with the elastomer-forming mixture in one operation. "Sufficiently impregnated" means that the interstices of the reinforcing layer are filled with the impregnating substance and should therefore be interpreted as "sufficiently impregnated."

One application of the method of the invention is 10.341MN/m ²
(1500 psi) or higher burst test pressure (1500 psi) or higher. − Standards, Recommended Practices, and Information Reporting” handbook expansion
(See HS150, 1977 edition) (Ref: Society of
Automotive Engineers Publication “Tube,
Pipe, Hose and Lubrication Fittings−
Standards, Recommended Practices,
Information Reports.”Handbook Supplement
HS150, 1977 Edition). In such structures, the reinforcement density is generally relatively high, e.g. in the range of at least 60%, preferably at least 75%.
is within the range of Previously known methods of manufacturing hoses of this type in which multiple reinforcing layers were used required a non-porous polymeric insulating layer between the reinforcing layers, primarily to prevent abrasion. The method of the present invention substantially reduces or even prevents this abrasion by completely impregnating the interstices, thus eliminating the need for such non-porous insulating layers.

One way to produce an inexpensive hose would be to reduce the wall thickness of the inner liner to a minimum.
Unfortunately, in hoses manufactured by the known method, there is often air in the interstices of the reinforcing layer, and if the inner liner is too thin, the inner liner can expand into these interstices and cause the hose to tear. Using the method of the present invention, this disadvantage can be overcome by providing sufficient impregnation to reduce the thickness of the inner liner.

The inner liner is impermeable to the impregnating agent and may be an elastomeric material (e.g., vulcanized rubber such as nitrile rubber, chlorinated polyethylene rubber or silicone rubber, polyester and
Thermoplastic rubbers or thermoplastic materials, such as polar elastoplastic linear mass copolymers, including polyether blocks sold by Pont Company as "Hytrel" (e.g.
Nylon (such as Nylon11) is fine.

The reinforcing material may be nylon, homogeneous or copolymers of propylene, rayon, aromatic polyamides (such as those sold under the trade name "Kevlar"), woven materials, glass or metals such as brass-coated steel wire. good. The reinforcement can be comprised of axial and helical components that can be laminated, woven, knitted or strung together to form a balanced structure. Alternatively, the reinforcing material can be used in a spiral wrap.

If desired, a loose woven fabric that is permeable to the liquid elastomer/forming impregnant used may be placed between the reinforcing layers, between the inner liner and the reinforcing layer, or between the reinforcing layers and the inner liner and the reinforcing layer. It can be provided in

An impregnating agent is an elastomer-forming reaction mixture consisting of components that are liquid at the impregnation temperature and chemically react to form an elastomer when cured. The impregnating agent may be one which produces a polyurethane elastomer or silicone rubber, or may be combined with a suitable co-reactant such as an epoxy resin, such as a copolymer rubber of amine-terminated butadiene and acrylonitrile (commercially available from BF Gudrich). A functional group-terminated liquid polymer such as those sold under the name "Hycar" may be used. The impregnating agent may also contain other additives, such as at least one selected from plasticizers, extenders, pigments and surface tension modifiers. One example of a polyurethane-forming reaction mixture is one consisting of a relatively high molecular weight polyol, a relatively low molecular weight diol, an isocyanate and optionally a catalyst, which reaction mixture is reacted to produce a No. 3,549,176, the fast-setting polyurethane-forming composition of this British application comprises a liquid poly(propylene glycol) polyol having a molecular weight of 400 or more; It consists of a liquid, low molecular weight diol having a molecular weight of less than 250, and a catalyst selected from liquid di(isocyanate phenyl)methane and a stannous salt of a liquid or polyol-soluble carboxylic or mineral acid. The viscosity of the impregnating agent at the impregnation temperature must not be too high, otherwise it will be difficult to achieve almost complete impregnation. The viscosity of the impregnating agent at the impregnation temperature is preferably 10 Ns/m ² (10,000 centipoise) or less, more preferably 5 Ns/m ² or less, advantageously 1 Ns/m ² or less. In determining the appropriate viscosity of the impregnating agent, the texture of the reinforcement is generally taken into account, as loosely woven reinforcements generally accept a significantly higher viscosity of the impregnating agent than tightly woven reinforcements. One advantage of the method of the invention is that complete impregnation generally requires the application of external pressure (e.g. by applying a vacuum to the container containing the impregnated article) in addition to the pressure due to the presence of the impregnating agent itself. This means that there is no.

After being impregnated into the reinforcement, the liquid impregnant reacts and hardens, typically accelerated by the application of heat. Heat can be applied before, during or after impregnation. If desired, further reinforcing layers can be added to the combination and the impregnation can be repeated.

Preferably, impregnation is carried out by passing the inner liner and reinforcing layer combination through an impregnation vessel. One method of impregnating the reinforcement with the impregnating agent to the desired extent is to add at least one layer of reinforcement, such as a braid, to a tube formed with an inner liner material and then pass the resulting tubular article vertically into an impregnated container. The orifice also serves to remove excess saturant from the assembly by passing it downward through an orifice located below the level of the saturant in the container. If desired, the impregnation agent can be cured and the assembly passed upwardly through the impregnation vessel to further coat the assembly with the same or a different material than the impregnation agent.

The inner liner and reinforcing layer combination is substantially self-supporting, ie, substantially retains its cross-sectional shape during impregnation without the use of mandrels. Alternatively, a mandrel may be used to support the product or it may be pressurized from within, for example if the final product is a "flat" hose.

One embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, which show in vertical section a combination of inner liner and reinforcing layer and a container impregnated therein.

The impregnating vessel 1 has an orifice 2 provided with a rubber seal 3 dimensioned to allow the passage of the tubular assembly 4 but to prevent the impregnating agent 5 from escaping from the vessel. The tubular combination 4 is 1
It consists of an inner liner 6 surrounded by one or more reinforcing layers 7. In using the container 1, the tubular assembly 4 is pulled out of the container 1 past the seal 3, which is pulled downwardly through the impregnating agent 5 and also serves to remove excess impregnating agent from the assembly. If desired, one or more coatings can be applied to the combination 4 with one or more substances of the same or different type as the impregnating agent, for example by pulling the combination 4 vertically upwards within the impregnation container 1. It can be provided in The impregnating agent can be thermally cured before, during or after impregnation or by application of hot air before, during and after impregnation.

After impregnation of the reinforcing layer with the impregnating agent, either before or after curing of the impregnating agent, an outer cover of, for example, an elastomeric material can be applied to the assembly, for example, by the methods described above or by extrusion methods.

One aspect of the invention is illustrated by the following example in which impregnation is carried out using the impregnation vessel shown in the accompanying drawings.

Example Two pieces of steel wire braided into a nylon tube with an inner diameter of 6.3 mm and an outer diameter of 9.4 mm and plated with brass.
Two layers were coated to create a combination with an internal diameter of 5.5 mm. A mesh wire having a diameter of 0.305 mm was coated onto the nylon tube using a prior art braiding machine.

A 1.3 m long piece of this product was immersed in dichloromethane, washed and dried, and then passed through a rubber seal provided at the bottom of a 300 ml metal container by extending the 40 mm length of the tube below the seal. The temperature of the tube is reduced to 40-45℃ by passing hot air through the tube.
It was raised to .

The following polyurethane-forming compositions were mixed and poured into a container around braid-reinforced nylon tubing.

Propylan D-2122 (e.g. Lankro) ² 75.0 g Ethane diol ¹ 9.3 g Anhydrous stannous chloride ¹ 0.75 g Pigment Dispersion 3373, e.g. from Chemical Products (Chiesia) Limited 3.0 g Liquid silicone (Dow Corning 0.3 g Isonate 143L (e.g. Upjohn) ³ 60.0 g 1 The stannous chloride was dissolved in the ethane diol before mixing with the other ingredients.

2 Ethylene oxide terminated poly(propylene glycol) diol with a molecular weight of 2000 3 Pure MDI and carbodiimide adducts of MDI This composition was measured on a Brookfield viscometer model LVF using spindle No. 1 at 12 rpm. It has an initial viscosity of 0.239 Ns/m ² at 21°C. None of the ingredients are dry, so it is assumed that the propylan and ethane diol contain a small percentage of water.

The hose was then pulled downwardly past the seal at a rate of about 14.2 mm/sec while stirring the mixture until only about 150 mm of the hose remained above the seal. After 20 minutes, the liquid composition reacted and cured into a solid elastomer, and the container and remainder were separated from the hose.

This procedure was repeated but in reverse, ie, the hose was pulled upwards to apply an additional thin coat of polyurethane to the outside of the hose. This coating procedure was repeated two more times to form a coating approximately 0.5 mm thick.

After standing for 7 days, a connecting tube was attached to each length of the resulting hose. The samples were subjected to shock testing using a square wave shock wave pressure of 43.98 MN/m ² at a frequency of 60 impulses/min with the hydraulic fluid at 93°C.

The sample had a failure pressure of 227.5 MN/m ² without failure after 333 and 300 impulse cycles.

EXAMPLE A nylon tube reinforced with braid as described in the example was immersed in dichloromethane, dried, and then a rubber seal placed at the bottom of a 1-volume container with an open top was placed over a length of about 40 mm of the tube. The part protruded below the seal and was passed through. The temperature of the tube was raised to approximately 50°C by passing hot air through the tube.

A composition consisting of the following three components was prepared and the three components were mixed at 60°C.

Ingredients A Epoxy resin (sold as Epikote 815 by Ciel) 2,2-di(4-hydroxy-phenyl) Flopane (sold as Bisphenol-A by BDH Chemicals Limited) 100g 24g Mixed at 120°C Component B Di-iso-octyl sebacateamine terminated butadiene-acrylonitrile copolymer (sold as Hycar 1300 x 16 by BF Gutdrich) 100g 300g Mixed and heated at 60°C Component C Liquid silicone (0.8 g sold by Dow Corning as Silicone DC200, 50 centistoc) Mixture (approx. 1) which had a viscosity of 5Ns/ ^m2
The volume was poured into a container around a nylon tube reinforced with a layer of braid. The tube was pulled downward through the seal at a rate of about 8.3 mm until about 150 mm of the tube remained above the seal. The temperature of the assembly was maintained at approximately 50°C for an additional hour and a half. Upon subsequent inspection of the hose, it was determined that the braid was fully impregnated with the impregnating agent.

[Brief explanation of drawings]

The accompanying drawing is a vertical cross-sectional view of an impregnating vessel used in carrying out the method of the invention. 4... Tubular article, 5... Reaction mixture, 7... Reinforcement layer.

Claims (1)

Claims: 1. At least one layer of reinforcing material is attached to a tube of polymeric material that will become the inner liner, the reinforcing material is immersed in a liquid reaction mixture, and the reaction mixture is then reacted and cured to form a solid state. A method of manufacturing a reinforced tubular article, characterized in that the liquid reaction mixture comprises a liquid elastomer-forming reaction mixture that satisfactorily impregnates the reinforcement by filling the gaps in the reinforcement. , said method. 2 a plurality of reinforcing layers are attached to the tube of polymeric material;
2. A method according to claim 1, wherein these layers are then impregnated with said reaction mixture in one operation. 3. The method according to claim 1 or 2, wherein the elastomer-forming liquid reaction mixture contains a component that reacts to form a solid polyurethane. 4 The elastomer-forming liquid reaction mixture contains a liquid poly(propylene glycol polyol) with a molecular weight of 500 or more, a liquid diol with a molecular weight of 250 or less, a liquid di(isocyanatophenyl)methane, and a liquid or carboxylic acid or mineral soluble in the polyol. 5. The method of claim 3, wherein the elastomer-forming liquid reaction mixture comprises a copolymer rubber of functionally terminated liquid butane diene and acrylonitrile and epoxy. 6. The method according to claim 1 or 2, wherein the elastomer-forming liquid reaction mixture has a viscosity of 10 Ns/m ² or less at the impregnation temperature. 7. The method according to any one of claims 1 to 5, wherein the viscosity of the elastomer-forming liquid reaction mixture is 5 Ns/m ² or less at the impregnation temperature. 8. A method according to any one of claims 1 to 5, wherein the viscosity of the elastomer-forming liquid reaction mixture is less than or equal to 1 Ns/m ² at the impregnation temperature. 9. The only or each reinforcing layer is made of metal. 10. A method according to any one of claims 1 to 8, comprising:
The method described in. 11. A method according to any one of claims 1 to 8, wherein the only or each reinforcing layer consists of a braid. 12. The method of any one of claims 1 to 10, wherein the or each reinforcing layer is helically wrapped around the inner liner. 13. A method according to any one of claims 1 to 12, wherein the reinforced inner liner is able to maintain substantially its cross-sectional shape during impregnation without the use of a mandrel. 14 Only one or each reinforcing layer is at least 75%
Claims 1 to 13 having a coverage of
The method described in any one of the paragraphs. 15 Claims 1 to 14 in which there are a plurality of reinforcing layers, and a non-porous polymeric insulation material is provided between the reinforcing layers.
The method described in any one of the paragraphs. 16 A substance permeable to the elastomer-forming liquid reaction mixture is placed between the inner liner and the sole reinforcing layer or layers, and/or between the reinforcing layers, if any. 16. A method according to any one of the claims 1 to 15 provided. 17. A method according to any one of claims 1 to 16, wherein no external pressure is applied to the reinforcing tubular article during the impregnation step. 18. A method according to any one of claims 1 to 17, wherein the reaction and curing of the reaction mixture is accelerated by applying heat. 19. According to any one of claims 1 to 18, wherein the assembly of the inner liner and the reinforcing layer or layers is passed downwardly through an impregnation vessel containing an elastomer-forming liquid reaction mixture. Method described.